Instruction:
Make a summary of the following Python 3 code
def configure(self, component, all_dependencies):
        ''' Ensure all config-time files have been generated. Return a
            dictionary of generated items.
        '''
        r = {}

        builddir = self.buildroot

        # only dependencies which are actually valid can contribute to the
        # config data (which includes the versions of all dependencies in its
        # build info) if the dependencies aren't available we can't tell what
        # version they are. Anything missing here should always be a test
        # dependency that isn't going to be used, otherwise the yotta build
        # command will fail before we get here
        available_dependencies = OrderedDict((k, v) for k, v in all_dependencies.items() if v)

        self.set_toplevel_definitions = ''
        if self.build_info_include_file is None:
            self.build_info_include_file, build_info_definitions = self.getBuildInfo(component.path, builddir)
            self.set_toplevel_definitions += build_info_definitions

        if self.config_include_file is None:
            self.config_include_file, config_definitions, self.config_json_file = self._getConfigData(available_dependencies, component, builddir, self.build_info_include_file)
            self.set_toplevel_definitions += config_definitions

        self.configured = True
        return {
            'merged_config_include': self.config_include_file,
               'merged_config_json': self.config_json_file,
               'build_info_include': self.build_info_include_file
        }

Response:
Configure the a
            dictionary.


Instruction:
How would you code a function in Python 3 to
generate all the top - level CMakeLists for this component and its dependencies

Response:
def generateRecursive(self, component, all_components, builddir=None, modbuilddir=None, processed_components=None, application=None):
        ''' generate top-level CMakeLists for this component and its
            dependencies: the CMakeLists are all generated in self.buildroot,
            which MUST be out-of-source

            !!! NOTE: experimenting with a slightly different way of doing
            things here, this function is a generator that yields any errors
            produced, so the correct use is:

            for error in gen.generateRecursive(...):
                print(error)
        '''
        assert(self.configured)

        if builddir is None:
            builddir = self.buildroot
        if modbuilddir is None:
            modbuilddir = os.path.join(builddir, 'ym')

        if processed_components is None:
            processed_components = dict()
        if not self.target:
            yield 'Target "%s" is not a valid build target' % self.target

        toplevel = not len(processed_components)

        logger.debug('generate build files: %s (target=%s)' % (component, self.target))
        # because of the way c-family language includes work we need to put the
        # public header directories of all components that this component
        # depends on (directly OR indirectly) into the search path, which means
        # we need to first enumerate all the direct and indirect dependencies
        recursive_deps = component.getDependenciesRecursive(
            available_components = all_components,
                          target = self.target,
                  available_only = True,
                            test = True
        )
        dependencies = component.getDependencies(
                  all_components,
                          target = self.target,
                  available_only = True,
                            test = True
        )

        for name, dep in dependencies.items():
            # if dep is a test dependency, then it might not be required (if
            # we're not building tests). We don't actually know at this point
            if not dep:
                if dep.isTestDependency():
                    logger.debug('Test dependency "%s" of "%s" is not installed.' % (name, component))
                else:
                    yield 'Required dependency "%s" of "%s" is not installed.' % (name, component)
        # ensure this component is assumed to have been installed before we
        # check for its dependencies, in case it has a circular dependency on
        # itself
        processed_components[component.getName()] = component
        new_dependencies = OrderedDict([(name,c) for name,c in dependencies.items() if c and not name in processed_components])
        self.generate(builddir, modbuilddir, component, new_dependencies, dependencies, recursive_deps, application, toplevel)

        logger.debug('recursive deps of %s:' % component)
        for d in recursive_deps.values():
            logger.debug('    %s' % d)

        processed_components.update(new_dependencies)
        for name, c in new_dependencies.items():
            for error in self.generateRecursive(
                c, all_components, os.path.join(modbuilddir, name), modbuilddir, processed_components, application=application
            ):
                yield error


Instruction:
Can you generate a brief explanation for the following Python 3 code
def _validateListedSubdirsExist(self, component):
        ''' Return true if all the subdirectories which this component lists in
            its module.json file exist (although their validity is otherwise
            not checked).

            If they don't, warning messages are printed.
        '''
        lib_subdirs = component.getLibs(explicit_only=True)
        bin_subdirs = component.getBinaries()

        ok = True
        for d in lib_subdirs:
            if not os.path.exists(os.path.join(component.path, d)):
                logger.warning(
                    "lib directory \"%s\" doesn't exist but is listed in the module.json file of %s", d, component
                )
                ok = False

        for d in bin_subdirs:
            if not os.path.exists(os.path.join(component.path, d)):
                logger.warning(
                    "bin directory \"%s\" doesn't exist but is listed in the module.json file of %s", d, component
                )
                ok = False

        return ok

Response:
Return True if all the subdirectories which this component lists in
            its module. json file exist and they are otherwise checked.


Instruction:
Implement a Python 3 function for
listing all sub - directories of the component.

Response:
def _listSubDirectories(self, component, toplevel):
        ''' return: {
                manual: [list of subdirectories with manual CMakeLists],
                  auto: [list of pairs: (subdirectories name to autogenerate, a list of source files in that dir)],
                   bin: {dictionary of subdirectory name to binary name},
                   lib: {dictionary of subdirectory name to binary name},
                  test: [list of directories that build tests],
              resource: [list of directories that contain resources]
            }
        '''
        manual_subdirs = []
        auto_subdirs = []
        header_subdirs = []
        lib_subdirs = component.getLibs()
        bin_subdirs = component.getBinaries()
        test_subdirs = []
        resource_subdirs = []
        # if the application or library is set to get the sources from top level ("."),
        # they'll be acumulated into a single array (top_sources below).
        top_sources = []
        start_on_top = "." in [os.path.normpath(x) for x in list(lib_subdirs.keys()) + list(bin_subdirs.keys())]
        for f in sorted(os.listdir(component.path)):
            if f in Ignore_Subdirs or f.startswith('.') or f.startswith('_'):
                continue
            check_cmakefile_path = os.path.join(f, 'CMakeLists.txt')
            if os.path.isfile(os.path.join(component.path, check_cmakefile_path)) and not \
                    component.ignores(check_cmakefile_path):
                self.checkStandardSourceDir(f, component)
                # if the subdirectory has a CMakeLists.txt in it (and it isn't
                # ignored), then delegate to that:
                manual_subdirs.append(f)
                # tests only supported in the `test` directory for now
                if f in ('test',):
                    test_subdirs.append(f)
            else:
                if os.path.isfile(os.path.join(component.path, f)):
                    # top level source: check if it should be included
                    if not component.ignores(f) and start_on_top:
                        sf = self.createSourceFile(f, os.path.join(component.path, f), ".")
                        if sf is not None:
                            top_sources.append(sf)
                else:
                    # otherwise, if the directory has source files, and is listed
                    # as a source/test directory, generate a CMakeLists in the
                    # corresponding temporary directory, and add that.
                    sources = self.containsSourceFiles(os.path.join(component.path, f), component)
                    if sources:
                        if f in ('test',):
                            auto_subdirs.append((f, sources))
                            test_subdirs.append(f)
                        elif start_on_top:
                            # include the sources in this directory only if it's not
                            # a potential test directory
                            from yotta.lib import validate
                            if not validate.isPotentialTestDir(f):
                                top_sources.extend(sources)
                                if f == component.getName():
                                    header_subdirs.append((f, sources))
                        elif os.path.normpath(f) in [fsutils.fullySplitPath(x)[0] for x in lib_subdirs] or \
                             os.path.normpath(f) in [fsutils.fullySplitPath(x)[0] for x in bin_subdirs]:
                            for full_subpath in list(lib_subdirs.keys()) + list(bin_subdirs.keys()):
                                if fsutils.fullySplitPath(full_subpath)[0] == os.path.normpath(f):
                                    # this might be a sub-sub directory, in which
                                    # case we need to re-calculate the sources just
                                    # for the part we care about:
                                    sources = self.containsSourceFiles(os.path.join(component.path, full_subpath), component)
                                    auto_subdirs.append((full_subpath, sources))
                        elif f == component.getName():
                            header_subdirs.append((f, sources))
                    elif toplevel and \
                         ((f in ('test',)) or \
                          (os.path.normpath(f) in lib_subdirs or start_on_top) or \
                          (os.path.normpath(f) in bin_subdirs or start_on_top) and not \
                          component.ignores(f)):
                        # (if there aren't any source files then do nothing)
                        # !!! FIXME: ensure this warning is covered in tests
                        logger.warning("subdirectory \"%s\" of %s was ignored because it doesn't appear to contain any source files", f, component)

            # 'resource' directory also has special meaning, but there's no
            # pattern for the files which might be in here:
            if f in ('resource',):
                resource_subdirs.append(os.path.join(component.path, f))

            # issue a warning if a differently cased or common misspelling of a
            # standard directory name was encountered:
            check_directory_name_cases = list(lib_subdirs.keys()) + list(bin_subdirs.keys()) + ['test', 'resource']
            if f.lower() in check_directory_name_cases + ['src'] and not \
               f in check_directory_name_cases and not \
               component.ignores(f):
                self.checkStandardSourceDir(f, component)
        if top_sources:
            # all the top level sources are grouped into a single cmake-generated directory
            # which is given the same name as the component
            auto_subdirs.append((component.getName(), top_sources))

        return {
            "manual": manual_subdirs,
              "auto": auto_subdirs,
           "headers": header_subdirs,
               "bin": {component.getName(): component.getName()} if (start_on_top and component.isApplication()) else bin_subdirs,
               "lib": {component.getName(): component.getName()} if (start_on_top and not component.isApplication()) else lib_subdirs,
              "test": test_subdirs,
          "resource": resource_subdirs
        }


Instruction:
How would you implement a function in Python 3 that
returns the path_to_config_header cmake_set_definitions

Response:
def _getConfigData(self, all_dependencies, component, builddir, build_info_header_path):
        ''' returns (path_to_config_header, cmake_set_definitions) '''
        # ordered_json, , read/write ordered json, internal
        from yotta.lib import ordered_json
        add_defs_header = ''
        set_definitions = ''
        # !!! backwards-compatible "TARGET_LIKE" definitions for the top-level
        # of the config. NB: THESE WILL GO AWAY
        definitions = []
        definitions.append(('TARGET', sanitizePreprocessorSymbol(self.target.getName())))
        definitions.append(('TARGET_LIKE_%s' % sanitizePreprocessorSymbol(self.target.getName()),None))

        # make the path to the build-info header available both to CMake and
        # in the preprocessor:
        full_build_info_header_path = replaceBackslashes(os.path.abspath(build_info_header_path))
        logger.debug('build info header include path: "%s"', full_build_info_header_path)
        definitions.append(('YOTTA_BUILD_INFO_HEADER', '"'+full_build_info_header_path+'"'))

        for target in self.target.getSimilarTo_Deprecated():
            if '*' not in target:
                definitions.append(('TARGET_LIKE_%s' % sanitizePreprocessorSymbol(target),None))

        merged_config = self.target.getMergedConfig()
        logger.debug('target configuration data: %s', merged_config)
        definitions += self._definitionsForConfig(merged_config, ['YOTTA', 'CFG'])

        add_defs_header += '// yotta config data (including backwards-compatible definitions)\n'

        for k, v in definitions:
            if v is not None:
                add_defs_header += '#define %s %s\n' % (k, v)
                set_definitions += 'set(%s %s)\n' % (k, v)
            else:
                add_defs_header += '#define %s\n' % k
                set_definitions += 'set(%s TRUE)\n' % k

        add_defs_header += '\n// version definitions\n'

        for dep in list(all_dependencies.values()) + [component]:
            add_defs_header += "#define YOTTA_%s_VERSION_STRING \"%s\"\n" % (sanitizePreprocessorSymbol(dep.getName()), str(dep.getVersion()))
            add_defs_header += "#define YOTTA_%s_VERSION_MAJOR %d\n" % (sanitizePreprocessorSymbol(dep.getName()), dep.getVersion().major())
            add_defs_header += "#define YOTTA_%s_VERSION_MINOR %d\n" % (sanitizePreprocessorSymbol(dep.getName()), dep.getVersion().minor())
            add_defs_header += "#define YOTTA_%s_VERSION_PATCH %d\n" % (sanitizePreprocessorSymbol(dep.getName()), dep.getVersion().patch())

        # add the component's definitions
        defines = component.getDefines()
        if defines:
            add_defs_header += "\n// direct definitions (defines.json)\n"
            for name, value in defines.items():
                add_defs_header += "#define %s %s\n" % (name, value)
            add_defs_header += '\n'

        # use -include <definitions header> instead of lots of separate
        # defines... this is compiler specific, but currently testing it
        # out for gcc-compatible compilers only:
        config_include_file = os.path.join(builddir, 'yotta_config.h')
        config_json_file    = os.path.join(builddir, 'yotta_config.json')
        set_definitions += 'set(YOTTA_CONFIG_MERGED_JSON_FILE \"%s\")\n' % replaceBackslashes(os.path.abspath(config_json_file))

        self._writeFile(
            config_include_file,
            '#ifndef __YOTTA_CONFIG_H__\n'+
            '#define __YOTTA_CONFIG_H__\n'+
            add_defs_header+
            '#endif // ndef __YOTTA_CONFIG_H__\n'
        )
        self._writeFile(
            config_json_file,
            ordered_json.dumps(merged_config)
        )
        return (config_include_file, set_definitions, config_json_file)


Instruction:
How would you explain what the following Python 3 function does
def getBuildInfo(self, sourcedir, builddir):
        ''' Write the build info header file, and return (path_to_written_header, set_cmake_definitions) '''
        cmake_defs = ''
        preproc_defs = '// yotta build info, #include YOTTA_BUILD_INFO_HEADER to access\n'
        # standard library modules
        import datetime
        # vcs, , represent version controlled directories, internal
        from yotta.lib import vcs

        now = datetime.datetime.utcnow()
        vcs_instance = vcs.getVCS(sourcedir)
        if self.build_uuid is None:
            import uuid
            self.build_uuid = uuid.uuid4()

        definitions = [
            ('YOTTA_BUILD_YEAR',   now.year,        'UTC year'),
            ('YOTTA_BUILD_MONTH',  now.month,       'UTC month 1-12'),
            ('YOTTA_BUILD_DAY',    now.day,         'UTC day 1-31'),
            ('YOTTA_BUILD_HOUR',   now.hour,        'UTC hour 0-24'),
            ('YOTTA_BUILD_MINUTE', now.minute,      'UTC minute 0-59'),
            ('YOTTA_BUILD_SECOND', now.second,      'UTC second 0-61'),
            ('YOTTA_BUILD_UUID',   self.build_uuid, 'unique random UUID for each build'),
        ]
        if vcs_instance is not None:
            commit_id = None
            repotype = vcs_instance.__class__.__name__
            try:
                commit_id = vcs_instance.getCommitId()
            except vcs.VCSNotInstalled as e:
                logger.warning('%s is not installed, VCS status build info is not available', repotype)
                commit_id = None
            except vcs.VCSError as e:
                logger.debug('%s', e)
                logger.warning(
                    'error detecting build info: "%s", build info is not available to the build. Please check that this is a valid %s repository!',
                    str(e).split('\n')[0],
                    repotype
                )
            if commit_id is not None:
                clean_state = int(vcs_instance.isClean())
                description = vcs_instance.getDescription()
                definitions += [
                    ('YOTTA_BUILD_VCS_ID',    commit_id,   'git or mercurial hash'),
                    ('YOTTA_BUILD_VCS_CLEAN', clean_state, 'evaluates true if the version control system was clean, otherwise false'),
                    ('YOTTA_BUILD_VCS_DESCRIPTION', description, 'git describe or mercurial equivalent')
                ]

        for d in definitions:
            preproc_defs += '#define %s %s // %s\n' % d
            cmake_defs   += 'set(%s "%s") # %s\n' % d

        buildinfo_include_file = os.path.join(builddir, 'yotta_build_info.h')
        self._writeFile(
            buildinfo_include_file,
            '#ifndef __YOTTA_BUILD_INFO_H__\n'+
            '#define __YOTTA_BUILD_INFO_H__\n'+
            preproc_defs+
            '#endif // ndef __YOTTA_BUILD_INFO_H__\n'
        )
        return (buildinfo_include_file, cmake_defs)

Response: Write the build info header file and return the path to the build info header and set_cmake_definitions


Instruction:
Can you tell what is the following Python 3 function doing
def generate(
            self, builddir, modbuilddir, component, active_dependencies, immediate_dependencies, all_dependencies, application, toplevel
        ):
        ''' active_dependencies is the dictionary of components that need to be
            built for this component, but will not already have been built for
            another component.
        '''

        include_root_dirs = ''
        if application is not None and component is not application:
            include_root_dirs += 'include_directories("%s")\n' % replaceBackslashes(application.path)

        include_sys_dirs = ''
        include_other_dirs = ''
        for name, c in itertools.chain(((component.getName(), component),), all_dependencies.items()):
            if c is not component and c.isTestDependency():
                continue
            include_root_dirs += 'include_directories("%s")\n' % replaceBackslashes(c.path)
            dep_sys_include_dirs = c.getExtraSysIncludes()
            for d in dep_sys_include_dirs:
                include_sys_dirs += 'include_directories(SYSTEM "%s")\n' % replaceBackslashes(os.path.join(c.path, d))
            dep_extra_include_dirs = c.getExtraIncludes()
            for d in dep_extra_include_dirs:
                include_other_dirs += 'include_directories("%s")\n' % replaceBackslashes(os.path.join(c.path, d))

        add_depend_subdirs = ''
        for name, c in active_dependencies.items():
            depend_subdir = replaceBackslashes(os.path.join(modbuilddir, name))
            relpath = replaceBackslashes(os.path.relpath(depend_subdir, self.buildroot))
            add_depend_subdirs += \
                'add_subdirectory(\n' \
                '   "%s"\n' \
                '   "${CMAKE_BINARY_DIR}/%s"\n' \
                ')\n' \
                % (depend_subdir, relpath)

        delegate_to_existing = None
        delegate_build_dir = None

        module_is_empty = False
        if os.path.isfile(os.path.join(component.path, 'CMakeLists.txt')) and not component.ignores('CMakeLists.txt'):
            # adding custom CMake is a promise to generate a library: so the
            # module is never empty in this case.
            delegate_to_existing = component.path
            add_own_subdirs = []
            logger.debug("delegate to build dir: %s", builddir)
            delegate_build_dir = os.path.join(builddir, 'existing')
        else:
            # !!! TODO: if they don't exist, that should possibly be a fatal
            # error, not just a warning
            self._validateListedSubdirsExist(component)

            subdirs = self._listSubDirectories(component, toplevel)
            manual_subdirs      = subdirs['manual']
            autogen_subdirs     = subdirs['auto']
            binary_subdirs      = subdirs['bin']
            lib_subdirs         = subdirs['lib']
            test_subdirs        = subdirs['test']
            resource_subdirs    = subdirs['resource']
            header_subdirs      = subdirs['headers']
            logger.debug("%s lib subdirs: %s, bin subdirs: %s", component, lib_subdirs, binary_subdirs)

            add_own_subdirs = []
            for f in manual_subdirs:
                if os.path.isfile(os.path.join(component.path, f, 'CMakeLists.txt')):
                    # if this module is a test dependency, then don't recurse
                    # to building its own tests.
                    if f in test_subdirs and component.isTestDependency():
                        continue
                    add_own_subdirs.append(
                        (os.path.join(component.path, f), f)
                    )
            # names of all directories at this level with stuff in: used to figure
            # out what to link automatically
            all_subdirs = manual_subdirs + [x[0] for x in autogen_subdirs]

            # first check if this module is empty:
            if component.isTestDependency():
                if len(autogen_subdirs) + len(add_own_subdirs) == 0:
                    module_is_empty = True
            else:
                if len(autogen_subdirs) + len(add_own_subdirs) <= len(test_subdirs):
                    module_is_empty = True

            # autogenerate CMakeLists for subdirectories as appropriate:
            for f, source_files in autogen_subdirs:
                if f in test_subdirs:
                    # if this module is a test dependency, then don't recurse
                    # to building its own tests.
                    if component.isTestDependency():
                        continue
                    self.generateTestDirList(
                        builddir, f, source_files, component, immediate_dependencies, toplevel=toplevel, module_is_empty=module_is_empty
                    )
                else:
                    if f in binary_subdirs:
                        is_executable = True
                        object_name = binary_subdirs[f]
                    else:
                        # not a test subdir or binary subdir: it must be a lib
                        # subdir
                        assert(f in lib_subdirs)
                        object_name = lib_subdirs[f]

                    for header_dir, header_files in header_subdirs:
                        source_files.extend(header_files)

                    self.generateSubDirList(
                                      builddir = builddir,
                                       dirname = f,
                                  source_files = source_files,
                                     component = component,
                                   all_subdirs = all_subdirs,
                        immediate_dependencies = immediate_dependencies,
                                   object_name = object_name,
                              resource_subdirs = resource_subdirs,
                                 is_executable = (f in binary_subdirs)
                    )
                add_own_subdirs.append(
                    (os.path.join(builddir, f), f)
                )

            # from now on, completely forget that this component had any tests
            # if it is itself a test dependency:
            if component.isTestDependency():
                test_subdirs = []

            # if we're not building anything other than tests, and this is a
            # library module (not a binary) then we need to generate a dummy
            # library so that this component can still be linked against
            if module_is_empty:
                if len(binary_subdirs):
                    logger.warning('nothing to build!')
                else:
                    add_own_subdirs.append(self.createDummyLib(
                        component, builddir, [x[0] for x in immediate_dependencies.items() if not x[1].isTestDependency()]
                    ))

        toolchain_file_path = os.path.join(builddir, 'toolchain.cmake')
        if toplevel:
            # generate the top-level toolchain file:
            template = jinja_environment.get_template('toolchain.cmake')
            file_contents = template.render({  #pylint: disable=no-member
                                   # toolchain files are provided in hierarchy
                                   # order, but the template needs them in reverse
                                   # order (base-first):
                "toolchain_files": self.target.getToolchainFiles()
            })
            self._writeFile(toolchain_file_path, file_contents)

        # generate the top-level CMakeLists.txt
        template = jinja_environment.get_template('base_CMakeLists.txt')

        relpath = os.path.relpath(builddir, self.buildroot)

        file_contents = template.render({ #pylint: disable=no-member
                            "toplevel": toplevel,
                         "target_name": self.target.getName(),
                     "set_definitions": self.set_toplevel_definitions,
                      "toolchain_file": toolchain_file_path,
                           "component": component,
                             "relpath": relpath,
                   "include_root_dirs": include_root_dirs,
                    "include_sys_dirs": include_sys_dirs,
                  "include_other_dirs": include_other_dirs,
                  "add_depend_subdirs": add_depend_subdirs,
                     "add_own_subdirs": add_own_subdirs,
                 "config_include_file": self.config_include_file,
                         "delegate_to": delegate_to_existing,
                  "delegate_build_dir": delegate_build_dir,
                 "active_dependencies": active_dependencies,
                     "module_is_empty": module_is_empty,
                      "cmake_includes": self.target.getAdditionalIncludes()
        })
        self._writeFile(os.path.join(builddir, 'CMakeLists.txt'), file_contents)

Response: Generates a new entry for the current version of the component.


Instruction:
How would you explain what the following Python 3 function does
def _getTags(repo):
    ''' return a dictionary of {tag: tarball_url}'''
    logger.debug('get tags for %s', repo)
    g = Github(settings.getProperty('github', 'authtoken'))
    repo = g.get_repo(repo)
    tags = repo.get_tags()
    logger.debug('tags for %s: %s', repo, [t.name for t in tags])
    return {t.name: _ensureDomainPrefixed(t.tarball_url) for t in tags}

Response: return a dictionary of tags for a given repository


Instruction:
Explain what the following Python 3 code does
def _getTipArchiveURL(repo):
    ''' return a string containing a tarball url '''
    g = Github(settings.getProperty('github', 'authtoken'))
    repo = g.get_repo(repo)
    return repo.get_archive_link('tarball')

Response: return a string containing a tarball url


Instruction:
Explain what the following Python 3 code does
def _getCommitArchiveURL(repo, commit):
    ''' return a string containing a tarball url '''
    g = Github(settings.getProperty('github', 'authtoken'))
    repo = g.get_repo(repo)
    return repo.get_archive_link('tarball', commit)

Response: return a string containing a tarball url


Instruction:
Can you write a function in Python 3 where it
unpacks the specified tarball into the specified directory

Response:
def _getTarball(url, into_directory, cache_key, origin_info=None):
    '''unpack the specified tarball url into the specified directory'''

    try:
        access_common.unpackFromCache(cache_key, into_directory)
    except KeyError as e:
        tok = settings.getProperty('github', 'authtoken')
        headers = {}
        if tok is not None:
            headers['Authorization'] = 'token ' + str(tok)

        logger.debug('GET %s', url)
        response = requests.get(url, allow_redirects=True, stream=True, headers=headers)
        response.raise_for_status()

        logger.debug('getting file: %s', url)
        logger.debug('headers: %s', response.headers)
        response.raise_for_status()

        # github doesn't exposes hashes of the archives being downloaded as far
        # as I can tell :(
        access_common.unpackTarballStream(
                    stream = response,
            into_directory = into_directory,
                      hash = {},
                 cache_key = cache_key,
               origin_info = origin_info
        )


Instruction:
Write a Python 3 function for
returning a github component for any github url including git + ssh:// git + http:// etc. or None if this is not a Github URL.

Response:
def createFromSource(cls, vs, name=None):
        ''' returns a github component for any github url (including
            git+ssh:// git+http:// etc. or None if this is not a Github URL.
            For all of these we use the github api to grab a tarball, because
            that's faster.

            Normally version will be empty, unless the original url was of the
            form: 'owner/repo @version' or 'url://...#version', which can be used
            to grab a particular tagged version.

            (Note that for github components we ignore the component name - it
             doesn't have to match the github module name)
        '''
        return GithubComponent(vs.location, vs.spec, vs.semantic_spec, name)


Instruction:
How would you code a function in Python 3 to
return a list of Version objects each with a tarball URL set

Response:
def availableVersions(self):
        ''' return a list of Version objects, each with a tarball URL set '''
        r = []
        for t in self._getTags():
            logger.debug("available version tag: %s", t)
            # ignore empty tags:
            if not len(t[0].strip()):
                continue
            try:
                r.append(GithubComponentVersion(t[0], t[0], url=t[1], name=self.name, cache_key=None))
            except ValueError:
                logger.debug('invalid version tag: %s', t)

        return r


Instruction:
Given the following Python 3 function, write the documentation
def availableTags(self):
        ''' return a list of GithubComponentVersion objects for all tags
        '''
        return [
            GithubComponentVersion(
                '', t[0], t[1], self.name, cache_key=_createCacheKey('tag', t[0], t[1], self.name)
            ) for t in self._getTags()
        ]

Response: return a list of GithubComponentVersion objects for all tags


Instruction:
How would you explain what the following Python 3 function does
def availableBranches(self):
        ''' return a list of GithubComponentVersion objects for the tip of each branch
        '''
        return [
            GithubComponentVersion(
                '', b[0], b[1], self.name, cache_key=None
            ) for b in _getBranchHeads(self.repo).items()
        ]

Response: return a list of GithubComponentVersion objects for the tip of each branch


Instruction:
How would you code a function in Python 3 to
return a GithubComponentVersion object for a specific commit if valid

Response:
def commitVersion(self):
        ''' return a GithubComponentVersion object for a specific commit if valid
        '''
        import re

        commit_match = re.match('^[a-f0-9]{7,40}$', self.tagOrBranchSpec(), re.I)
        if commit_match:
            return GithubComponentVersion(
                '', '', _getCommitArchiveURL(self.repo, self.tagOrBranchSpec()), self.name, cache_key=None
            )

        return None


Instruction:
Here you have a function in Python 3, explain what it does
def createFromSource(cls, vs, name=None):
        ''' returns a hg component for any hg:// url, or None if this is not
            a hg component.

            Normally version will be empty, unless the original url was of the
            form 'hg+ssh://...#version', which can be used to grab a particular
            tagged version.
        '''
        # strip hg of the url scheme:
        if vs.location.startswith('hg+'):
            location = vs.location[3:]
        else:
            location = vs.location
        return HGComponent(location, vs.spec)

Response: returns a hg component for any hg:// url or None if this is not


Instruction:
How would you explain what the following Python 3 function does
def dropRootPrivs(fn):
    ''' decorator to drop su/sudo privilages before running a function on
        unix/linux.
        The *real* uid is modified, so privileges are permanently dropped for
        the process. (i.e. make sure you don't need to do

        If there is a SUDO_UID environment variable, then we drop to that,
        otherwise we drop to nobody.
    '''

    def wrapped_fn(*args, **kwargs):
        q = multiprocessing.Queue()
        p = multiprocessing.Process(target=_dropPrivsReturnViaQueue, args=(q, fn, args, kwargs))
        p.start()

        r = None
        e = None
        while True:
            msg = q.get()
            if msg[0] == 'return':
                r = msg[1]
            if msg[0] == 'exception':
                e = msg[1](msg[2])
            if msg[0] == 'finish':
                # if the command raised an exception, propagate this:
                if e is not None:
                    raise e #pylint: disable=raising-bad-type
                return r

    return wrapped_fn

Response: decorator to drop root privilages before running a function on the system


Instruction:
Here you have a function in Python 3, explain what it does
def installAndBuild(args, following_args):
    ''' Perform the build command, but provide detailed error information.
        Returns {status:0, build_status:0, generate_status:0, install_status:0} on success.
        If status: is nonzero there was some sort of error. Other properties
        are optional, and may not be set if that step was not attempted.
    '''
    build_status = generate_status = install_status = 0

    if not hasattr(args, 'build_targets'):
        vars(args)['build_targets'] = []

    if 'test' in args.build_targets:
        logging.error('Cannot build "test". Use "yotta test" to run tests.')
        return {'status':1}

    cwd = os.getcwd()
    c = validate.currentDirectoryModule()
    if not c:
        return {'status':1}

    try:
        target, errors = c.satisfyTarget(args.target, additional_config=args.config)
    except access_common.AccessException as e:
        logging.error(e)
        return {'status':1}
    if errors:
        for error in errors:
            logging.error(error)
        return {'status':1}

    # run the install command before building, we need to add some options the
    # install command expects to be present to do this:
    vars(args)['component'] = None
    vars(args)['act_globally'] = False
    if not hasattr(args, 'install_test_deps'):
        if 'all_tests' in args.build_targets:
            vars(args)['install_test_deps'] = 'all'
        elif not len(args.build_targets):
            vars(args)['install_test_deps'] = 'own'
        else:
            # If the named build targets include tests from other modules, we
            # need to install the deps for those modules. To do this we need to
            # be able to tell which module a library belongs to, which is not
            # straightforward (especially if there is custom cmake involved).
            # That's why this is 'all', and not 'none'.
            vars(args)['install_test_deps'] = 'all'

    # install may exit non-zero for non-fatal errors (such as incompatible
    # version specs), which it will display
    install_status = install.execCommand(args, [])

    builddir = os.path.join(cwd, 'build', target.getName())

    all_deps = c.getDependenciesRecursive(
                      target = target,
        available_components = [(c.getName(), c)],
                        test = True
    )

    # if a dependency is missing the build will almost certainly fail, so don't try
    missing = 0
    for d in all_deps.values():
        if not d and not (d.isTestDependency() and args.install_test_deps != 'all'):
            logging.error('%s not available' % os.path.split(d.path)[1])
            missing += 1
    if missing:
        logging.error('Missing dependencies prevent build. Use `yotta ls` to list them.')
        return {'status': 1, 'install_status':install_status, 'missing_status':missing}

    generator = cmakegen.CMakeGen(builddir, target)
    # only pass available dependencies to
    config = generator.configure(c, all_deps)
    logging.debug("config done, merged config: %s", config['merged_config_json'])

    script_environment = {
        'YOTTA_MERGED_CONFIG_FILE': config['merged_config_json']
    }
    # run pre-generate scripts for all components:
    runScriptWithModules(c, all_deps.values(), 'preGenerate', script_environment)

    app = c if len(c.getBinaries()) else None
    for error in generator.generateRecursive(c, all_deps, builddir, application=app):
        logging.error(error)
        generate_status = 1

    logging.debug("generate done.")
    # run pre-build scripts for all components:
    runScriptWithModules(c, all_deps.values(), 'preBuild', script_environment)

    if (not hasattr(args, 'generate_only')) or (not args.generate_only):
        error = target.build(
                builddir, c, args, release_build=args.release_build,
                build_args=following_args, targets=args.build_targets,
                release_no_debug_info_build=args.release_no_debug_info_build
        )

        if error:
            logging.error(error)
            build_status = 1
        else:
            # post-build scripts only get run if we were successful:
            runScriptWithModules(c, all_deps.values(), 'postBuild', script_environment)

        if install_status:
            logging.warning(
                "There were also errors installing and resolving dependencies, "+
                "which may have caused the build failure: see above, or run "+
                "`yotta install` for details."
            )

    return {
                'status': build_status or generate_status or install_status,
        'missing_status': missing,
          'build_status': build_status,
       'generate_status': generate_status,
        'install_status': install_status
    }

Response: Perform the install and build command.


Instruction:
Can you generate the documentation for the following Python 3 function
def _friendlyAuthError(fn):
    ''' Decorator to print a friendly you-are-not-authorised message. Use
        **outside** the _handleAuth decorator to only print the message after
        the user has been given a chance to login. '''
    @functools.wraps(fn)
    def wrapped(*args, **kwargs):
        try:
            return fn(*args, **kwargs)
        except requests.exceptions.HTTPError as e:
            if e.response.status_code == requests.codes.unauthorized: #pylint: disable=no-member
                logger.error('insufficient permission')
            elif e.response.status_code == requests.codes.bad and 'jwt has expired' in e.response.text.lower(): #pylint: disable=no-member
                logger.error('server returned status %s: %s', e.response.status_code, e.response.text)
                logger.error('Check that your system clock is set accurately!')
            else:
                logger.error('server returned status %s: %s', e.response.status_code, e.response.text)
            raise
    return wrapped

Response:
Decorator to print a friendly you - are - not - authorised message. Use
 ArcGIS s _handleAuth decorator to only print the message after the user has given a chance to login.


Instruction:
Can you create a Python 3 function that
returns a decorator to swallow a requests exception for modules that are not accessible without logging in and turn it into an Unavailable exception.

Response:
def _raiseUnavailableFor401(message):
    ''' Returns a decorator to swallow a requests exception for modules that
        are not accessible without logging in, and turn it into an Unavailable
        exception.
    '''
    def __raiseUnavailableFor401(fn):
        def wrapped(*args, **kwargs):
            try:
                return fn(*args, **kwargs)
            except requests.exceptions.HTTPError as e:
                if e.response.status_code == requests.codes.unauthorized:
                    raise access_common.Unavailable(message)
                else:
                    raise
        return wrapped
    return __raiseUnavailableFor401


Instruction:
Can you create a Python 3 function that
publishes a tarblob to the registry.

Response:
def publish(namespace, name, version, description_file, tar_file, readme_file,
            readme_file_ext, registry=None):
    ''' Publish a tarblob to the registry, if the request fails, an exception
        is raised, which either triggers re-authentication, or is turned into a
        return value by the decorators. (If successful, the decorated function
        returns None)
    '''
    registry = registry or Registry_Base_URL

    url = '%s/%s/%s/versions/%s' % (
        registry,
        namespace,
        name,
        version
    )

    if readme_file_ext == '.md':
        readme_section_name = 'readme.md'
    elif readme_file_ext == '':
        readme_section_name = 'readme'
    else:
        raise ValueError('unsupported readme type: "%s"' % readme_file_ext)

    # description file is in place as text (so read it), tar file is a file
    body = OrderedDict([('metadata', (None, description_file.read(),'application/json')),
                        ('tarball',('tarball', tar_file)),
                        (readme_section_name, (readme_section_name, readme_file))])

    headers = _headersForRegistry(registry)

    response = requests.put(url, headers=headers, files=body)
    response.raise_for_status()

    return None


Instruction:
Can you generate a brief explanation for the following Python 3 code
def unpublish(namespace, name, version, registry=None):
    ''' Try to unpublish a recently published version. Return any errors that
        occur.
    '''
    registry = registry or Registry_Base_URL

    url = '%s/%s/%s/versions/%s' % (
        registry,
        namespace,
        name,
        version
    )

    headers = _headersForRegistry(registry)
    response = requests.delete(url, headers=headers)
    response.raise_for_status()

    return None

Response: Try to unpublish a recently published version. Return any errors that occur.


Instruction:
Make a summary of the following Python 3 code
def listOwners(namespace, name, registry=None):
    ''' List the owners of a module or target (owners are the people with
        permission to publish versions and add/remove the owners).
    '''
    registry = registry or Registry_Base_URL

    url = '%s/%s/%s/owners' % (
        registry,
        namespace,
        name
    )

    request_headers = _headersForRegistry(registry)

    response = requests.get(url, headers=request_headers)

    if response.status_code == 404:
        logger.error('no such %s, "%s"' % (namespace[:-1], name))
        return None

    # raise exceptions for other errors - the auth decorators handle these and
    # re-try if appropriate
    response.raise_for_status()

    return ordered_json.loads(response.text)

Response: List the owners of a module or target.


Instruction:
Can you generate the documentation for the following Python 3 function
def removeOwner(namespace, name, owner, registry=None):
    ''' Remove an owner for a module or target (owners are the people with
        permission to publish versions and add/remove the owners).
    '''
    registry = registry or Registry_Base_URL

    url = '%s/%s/%s/owners/%s' % (
        registry,
        namespace,
        name,
        owner
    )

    request_headers = _headersForRegistry(registry)

    response = requests.delete(url, headers=request_headers)

    if response.status_code == 404:
        logger.error('no such %s, "%s"' % (namespace[:-1], name))
        return

    # raise exceptions for other errors - the auth decorators handle these and
    # re-try if appropriate
    response.raise_for_status()

    return True

Response: Remove an owner for a module or target.


Instruction:
Write a Python 3 function that can
set the api key for accessing a specific registry.

Response:
def setAPIKey(registry, api_key):
    ''' Set the api key for accessing a registry. This is only necessary for
        development/test registries.
    '''
    if (registry is None) or (registry == Registry_Base_URL):
        return
    sources = _getSources()
    source = None
    for s in sources:
        if _sourceMatches(s, registry):
            source = s
    if source is None:
        source = {
           'type':'registry',
            'url':registry,
        }
        sources.append(source)
    source['apikey'] = api_key
    settings.set('sources', sources)


Response: Return the user s public key


Instruction:
How would you implement a function in Python 3 that
gets the authentication data for a specific user in the registry.

Response:
def getAuthData(registry=None):
    ''' Poll the registry to get the result of a completed authentication
        (which, depending on the authentication the user chose or was directed
        to, will include a github or other access token)
    '''
    registry = registry or Registry_Base_URL
    url = '%s/tokens' % (
        registry
    )

    request_headers = _headersForRegistry(registry)

    logger.debug('poll for tokens... %s', request_headers)

    try:
        response = requests.get(url, headers=request_headers)
    except requests.RequestException as e:
        logger.debug(str(e))
        return None

    if response.status_code == requests.codes.unauthorized: #pylint: disable=no-member
        logger.debug('Unauthorised')
        return None
    elif response.status_code == requests.codes.not_found: #pylint: disable=no-member
        logger.debug('Not Found')
        return None

    body = response.text
    logger.debug('auth data response: %s' % body);
    r = {}

    parsed_response = ordered_json.loads(body)

    if 'error' in parsed_response:
        raise AuthError(parsed_response['error'])

    for token in parsed_response:
        if 'provider' in token and token['provider'] and 'accessToken' in token:
            r[token['provider']] = token['accessToken']
            break

    logger.debug('parsed auth tokens %s' % r);
    return r


Instruction:
Can you implement a function in Python 3 that
returns a registry component for anything that s a valid package name

Response:
def createFromSource(cls, vs, name, registry):
        ''' returns a registry component for anything that's a valid package
            name (this does not guarantee that the component actually exists in
            the registry: use availableVersions() for that).
        '''
        # we deliberately allow only lowercase, hyphen, and (unfortunately)
        # numbers in package names, to reduce the possibility of confusingly
        # similar names: if the name doesn't match this then escalate to make
        # the user fix it. Targets also allow +
        if registry == 'targets':
            name_match = re.match('^[a-z]+[a-z0-9+-]*$', name)
            if not name_match:
                raise access_common.AccessException(
                    'Target name "%s" is not valid (must contain only lowercase letters, hyphen, plus, and numbers)' % name
                )
        else:
            name_match = re.match('^[a-z]+[a-z0-9-]*$', name)
            if not name_match:
                raise access_common.AccessException(
                    'Module name "%s" is not valid (must contain only lowercase letters, hyphen, and numbers)' % name
                )
        assert(vs.semantic_spec)
        return RegistryThing(name, vs.semantic_spec, registry)


Instruction:
Can you create a Python 3 function that
reads a list of files and merge them with the current settings.

Response:
def read(self, filenames):
        '''' Read a list of files. Their configuration values are merged, with
             preference to values from files earlier in the list.
        '''
        for fn in filenames:
            try:
                self.configs[fn] = ordered_json.load(fn)
            except IOError:
                self.configs[fn] = OrderedDict()
            except Exception as e:
                self.configs[fn] = OrderedDict()
                logging.warning(
                    "Failed to read settings file %s, it will be ignored. The error was: %s",
                    fn, e
                )


Instruction:
Can you tell what is the following Python 3 function doing
def get(self, path):
        ''' return a configuration value

            usage:
                get('section.property')

            Note that currently array indexes are not supported. You must
            get the whole array.

            returns None if any path element or the property is missing
        '''
        path = _splitPath(path)
        for config in self.configs.values():
            cur = config
            for el in path:
                if el in cur:
                    cur = cur[el]
                else:
                    cur = None
                    break
            if cur is not None:
                return cur
        return None

Response: get a configuration value for a given path element


Instruction:
Can you generate a brief explanation for the following Python 3 code
def set(self, path, value=None, filename=None):
        ''' Set a configuration value. If no filename is specified, the
            property is set in the first configuration file. Note that if a
            filename is specified and the property path is present in an
            earlier filename then set property will be hidden.

            usage:
                set('section.property', value='somevalue')

            Note that currently array indexes are not supported. You must
            set the whole array.
        '''
        if filename is None:
            config = self._firstConfig()[1]
        else:
            config = self.configs[filename]

        path = _splitPath(path)
        for el in path[:-1]:
            if el in config:
                config = config[el]
            else:
                config[el] = OrderedDict()
                config = config[el]
        config[path[-1]] = value

Response: Set a configuration value.


Instruction:
Can you generate the documentation for the following Python 3 function
def islast(generator):
    ''' indicate whether the current item is the last one in a generator
    '''
    next_x = None
    first = True
    for x in generator:
        if not first:
            yield (next_x, False)
        next_x = x
        first = False
    if not first:
        yield (next_x, True)

Response: indicate whether the current item is the last one in a generator


Instruction:
Make a summary of the following Python 3 code
def remoteComponentFor(name, version_required, registry='modules'):
    ''' Return a RemoteComponent sublclass for the specified component name and
        source url (or version specification)
        Raises an exception if any arguments are invalid.
    '''

    try:
        vs = sourceparse.parseSourceURL(version_required)
    except ValueError as e:
        raise access_common.Unavailable(
            '%s' % (e)
        )

    if vs.source_type == 'registry':
        if registry not in ('modules', 'targets'):
            raise Exception('no known registry namespace "%s"' % registry)
        return registry_access.RegistryThing.createFromSource(
            vs, name, registry=registry
        )
    elif vs.source_type == 'github':
        return github_access.GithubComponent.createFromSource(vs, name)
    elif vs.source_type == 'git':
        return git_access.GitComponent.createFromSource(vs, name)
    elif vs.source_type == 'hg':
        return hg_access.HGComponent.createFromSource(vs, name)
    else:
        raise Exception('unsupported module source: "%s"' % vs.source_type)

Response: Returns a RemoteComponent sublclass for the specified component name and version specification.


Instruction:
Implement a Python 3 function for
returning a Component or Target for the specified version from the specified list of search paths. If update is True then only update the Component and Target if it is installed via a symlink. If update is False then return None.

Response:
def satisfyVersionFromSearchPaths(name, version_required, search_paths, update=False, type='module', inherit_shrinkwrap=None):
    ''' returns a Component/Target for the specified version, if found in the
        list of search paths. If `update' is True, then also check for newer
        versions of the found component, and update it in-place (unless it was
        installed via a symlink).
    '''
    # Pack, , base class for targets and components, internal
    from yotta.lib import pack

    v = None
    try:
        sv = sourceparse.parseSourceURL(version_required)
    except ValueError as e:
        logging.error(e)
        return None

    try:
        local_version = searchPathsFor(
            name,
            sv.semanticSpec(),
            search_paths,
            type,
            inherit_shrinkwrap = inherit_shrinkwrap
        )
    except pack.InvalidDescription as e:
        logger.error(e)
        return None

    logger.debug("%s %s locally" % (('found', 'not found')[not local_version], name))
    if local_version:
        if update and not local_version.installedLinked():
            #logger.debug('attempt to check latest version of %s @%s...' % (name, version_required))
            v = latestSuitableVersion(name, version_required, registry=_registryNamespaceForType(type))
            if local_version:
                local_version.setLatestAvailable(v)

        # if we don't need to update, then we're done
        if local_version.installedLinked() or not local_version.outdated():
            logger.debug("satisfy component from directory: %s" % local_version.path)
            # if a component exists (has a valid description file), and either is
            # not outdated, or we are not updating
            if name != local_version.getName():
                raise Exception('Component %s found in incorrectly named directory %s (%s)' % (
                    local_version.getName(), name, local_version.path
                ))
            return local_version

        # otherwise, we need to update the installed component
        logger.info('update outdated: %s@%s -> %s' % (
            name,
            local_version.getVersion(),
            v
        ))
        # must rm the old component before continuing
        fsutils.rmRf(local_version.path)
        return _satisfyVersionByInstallingVersion(
            name, version_required, local_version.path, v, type=type, inherit_shrinkwrap=inherit_shrinkwrap
        )
    return None


Instruction:
Can you implement a function in Python 3 that
returns a Component or Target for the specified name + version requirement into a subdirectory of working_directory

Response:
def satisfyVersionByInstalling(name, version_required, working_directory, type='module', inherit_shrinkwrap=None):
    ''' installs and returns a Component/Target for the specified name+version
        requirement, into a subdirectory of `working_directory'
    '''
    v = latestSuitableVersion(name, version_required, _registryNamespaceForType(type))
    install_into = os.path.join(working_directory, name)
    return _satisfyVersionByInstallingVersion(
        name, version_required, install_into, v, type=type, inherit_shrinkwrap = inherit_shrinkwrap
    )


Instruction:
How would you explain what the following Python 3 function does
def _satisfyVersionByInstallingVersion(name, version_required, working_directory, version, type='module', inherit_shrinkwrap=None):
    ''' installs and returns a Component/Target for the specified version requirement into
        'working_directory' using the provided remote version object.
        This function is not normally called via `satisfyVersionByInstalling',
        which looks up a suitable remote version object.
    '''
    assert(version)
    logger.info('download %s', version)
    version.unpackInto(working_directory)
    r = _clsForType(type)(working_directory, inherit_shrinkwrap = inherit_shrinkwrap)
    if not r:
        raise Exception(
            'Dependency "%s":"%s" is not a valid %s.' % (name, version_required, type)
        )
    if name != r.getName():
        raise Exception('%s %s (specification %s) has incorrect name %s' % (
            type, name, version_required, r.getName()
        ))
    # error code deliberately ignored here for now, it isn't clear what the
    # behaviour should be (abort? remove the unpacked state then abort?
    # continue?)
    r.runScript('postInstall')
    return r

Response: returns a Component or Target object that is suitable for the specified version requirement into the specified working_directory


Instruction:
Implement a function in Python 3 to
return a Component or Target for the specified version

Response:
def satisfyVersion(
        name,
        version_required,
        available,
        search_paths,
        working_directory,
        update_installed=None,
        type='module',  # or 'target'
        inherit_shrinkwrap=None
    ):
    ''' returns a Component/Target for the specified version (either to an already
        installed copy (from the available list, or from disk), or to a newly
        downloaded one), or None if the version could not be satisfied.

        update_installed = None / 'Update'
            None:   prevent any attempt to look for new versions if the
                    component/target already exists
            Update: replace any existing version with the newest available, if
                    the newest available has a higher version
    '''

    r = satisfyFromAvailable(name, available, type=type)
    if r is not None:
        if not sourceparse.parseSourceURL(version_required).semanticSpecMatches(r.getVersion()):
            raise access_common.SpecificationNotMet(
                "Installed %s %s doesn't match specification %s" % (type, name, version_required)
            )
        return r

    r = satisfyVersionFromSearchPaths(
        name,
        version_required,
        search_paths,
        (update_installed == 'Update'),
        type = type,
        inherit_shrinkwrap = inherit_shrinkwrap
    )
    if r is not None:
        return r

    return satisfyVersionByInstalling(
        name, version_required, working_directory, type=type, inherit_shrinkwrap = inherit_shrinkwrap
    )


Instruction:
Can you tell what is the following Python 3 function doing
def sourceDirValidationError(dirname, component_name):
    ''' validate source directory names in components '''
    if dirname == component_name:
        return 'Module %s public include directory %s should not contain source files' % (component_name, dirname)
    elif dirname.lower() in ('source', 'src') and dirname != 'source':
        return 'Module %s has non-standard source directory name: "%s" should be "source"' % (component_name, dirname)
    elif isPotentialTestDir(dirname) and dirname != 'test':
        return 'Module %s has non-standard test directory name: "%s" should be "test"' % (component_name, dirname)
    elif not Source_Dir_Regex.match(dirname):
        corrected = Source_Dir_Invalid_Regex.sub('', dirname.lower())
        if not corrected:
            corrected = 'source'
        return 'Module %s has non-standard source directory name: "%s" should be "%s"' % (component_name, dirname, corrected)
    else:
        return None

Response: validate source directory names in components


Instruction:
Implement a function in Python 3 to
print information about outdated modules, return 0 if there is nothing to be done and nonzero otherwise

Response:
def displayOutdated(modules, dependency_specs, use_colours):
    ''' print information about outdated modules,
        return 0 if there is nothing to be done and nonzero otherwise
    '''
    if use_colours:
        DIM    = colorama.Style.DIM       #pylint: disable=no-member
        NORMAL = colorama.Style.NORMAL    #pylint: disable=no-member
        BRIGHT = colorama.Style.BRIGHT    #pylint: disable=no-member
        YELLOW = colorama.Fore.YELLOW     #pylint: disable=no-member
        RED    = colorama.Fore.RED        #pylint: disable=no-member
        GREEN  = colorama.Fore.GREEN      #pylint: disable=no-member
        RESET  = colorama.Style.RESET_ALL #pylint: disable=no-member
    else:
        DIM = BRIGHT = YELLOW = RED = GREEN = RESET = u''

    status = 0

    # access, , get components, internal
    from yotta.lib import access
    from yotta.lib import access_common
    # sourceparse, , parse version source urls, internal
    from yotta.lib import sourceparse

    for name, m in modules.items():
        if m.isTestDependency():
            continue
        try:
            latest_v = access.latestSuitableVersion(name, '*', registry='modules', quiet=True)
        except access_common.Unavailable as e:
            latest_v = None

        if not m:
            m_version = u' ' + RESET + BRIGHT + RED + u"missing" + RESET
        else:
            m_version = DIM + u'@%s' % (m.version)
        if not latest_v:
            print(u'%s%s%s%s not available from the registry%s' % (RED, name, m_version, NORMAL, RESET))
            status = 2
            continue
        elif not m or m.version < latest_v:
            update_prevented_by = ''
            if m:
                specs_preventing_update = [
                    x for x in dependency_specs
                    if x.name == name and not
                       sourceparse.parseSourceURL(x.nonShrinkwrappedVersionReq()).semanticSpecMatches(latest_v)
                ]
                shrinkwrap_prevents_update = [
                    x for x in dependency_specs
                    if x.name == name and x.isShrinkwrapped() and not
                       sourceparse.parseSourceURL(x.versionReq()).semanticSpecMatches(latest_v)
                ]
                if len(specs_preventing_update):
                    update_prevented_by = ' (update prevented by specifications: %s)' % (
                        ', '.join(['%s from %s' % (x.version_req, x.specifying_module) for x in specs_preventing_update])
                    )
                if len(shrinkwrap_prevents_update):
                    update_prevented_by += ' yotta-shrinkwrap.json prevents update'
                if m.version.major() < latest_v.major():
                    # major versions being outdated might be deliberate, so not
                    # that bad:
                    colour = GREEN
                elif m.version.minor() < latest_v.minor():
                    # minor outdated versions is moderately bad
                    colour = YELLOW
                else:
                    # patch-outdated versions is really bad, because there should
                    # be no reason not to update:
                    colour = RED
            else:
                colour = RED
            print(u'%s%s%s latest: %s%s%s%s' % (name, m_version, RESET, colour, latest_v.version, update_prevented_by, RESET))
            if not status:
                status = 1
    return status


Instruction:
How would you implement a function in Python 3 that
reads the. yotta_origin. json file and return the value of the url property.

Response:
def origin(self):
        ''' Read the .yotta_origin.json file (if present), and return the value
            of the 'url' property '''
        if self.origin_info is None:
            self.origin_info = {}
            try:
                self.origin_info = ordered_json.load(os.path.join(self.path, Origin_Info_Fname))
            except IOError:
                pass
        return self.origin_info.get('url', None)


Instruction:
How would you explain what the following Python 3 function does
def outdated(self):
        ''' Return a truthy object if a newer suitable version is available,
            otherwise return None.
            (in fact the object returned is a ComponentVersion that can be used
             to get the newer version)
        '''
        if self.latest_suitable_version and self.latest_suitable_version > self.version:
            return self.latest_suitable_version
        else:
            return None

Response: Return a truthy object if a newer suitable version is available return None otherwise


Instruction:
Can you generate a brief explanation for the following Python 3 code
def commitVCS(self, tag=None):
        ''' Commit the current working directory state (or do nothing if the
            working directory is not version controlled)
        '''
        if not self.vcs:
            return
        self.vcs.commit(message='version %s' % tag, tag=tag)

Response: Commit the current working directory state


Instruction:
How would you implement a function in Python 3 that
tests if this module ignores the file at path.

Response:
def ignores(self, path):
        ''' Test if this module ignores the file at "path", which must be a
            path relative to the root of the module.

            If a file is within a directory that is ignored, the file is also
            ignored.
        '''
        test_path = PurePath('/', path)

        # also check any parent directories of this path against the ignore
        # patterns:
        test_paths = tuple([test_path] + list(test_path.parents))

        for exp in self.ignore_patterns:
            for tp in test_paths:
                if tp.match(exp):
                    logger.debug('"%s" ignored ("%s" matched "%s")', path, tp, exp)
                    return True
        return False


Instruction:
Write a Python 3 script for
writing the current component description to a package description file in the component directory.

Response:
def writeDescription(self):
        ''' Write the current (possibly modified) component description to a
            package description file in the component directory.
        '''
        ordered_json.dump(os.path.join(self.path, self.description_filename), self.description)
        if self.vcs:
            self.vcs.markForCommit(self.description_filename)


Instruction:
How would you code a function in Python 3 to
write a tarball of the current component and target to the file object file_object which must already be opened at position 0

Response:
def generateTarball(self, file_object):
        ''' Write a tarball of the current component/target to the file object
            "file_object", which must already be open for writing at position 0
        '''
        archive_name = '%s-%s' % (self.getName(), self.getVersion())
        def filterArchive(tarinfo):
            if tarinfo.name.find(archive_name) == 0 :
                unprefixed_name = tarinfo.name[len(archive_name)+1:]
                tarinfo.mode &= 0o775
            else:
                unprefixed_name = tarinfo.name
            if self.ignores(unprefixed_name):
                return None
            else:
                return tarinfo
        with tarfile.open(fileobj=file_object, mode='w:gz') as tf:
            logger.info('generate archive extracting to "%s"' % archive_name)
            tf.add(self.path, arcname=archive_name, filter=filterArchive)


Instruction:
Implement a function in Python 3 to
publish the object to the appropriate registry. Returns a description of any anyErrors that occured or None if successful.

Response:
def publish(self, registry=None):
        ''' Publish to the appropriate registry, return a description of any
            errors that occured, or None if successful.
            No VCS tagging is performed.
        '''
        if (registry is None) or (registry == registry_access.Registry_Base_URL):
            if 'private' in self.description and self.description['private']:
                return "this %s is private and cannot be published" % (self.description_filename.split('.')[0])
        upload_archive = os.path.join(self.path, 'upload.tar.gz')
        fsutils.rmF(upload_archive)
        fd = os.open(upload_archive, os.O_CREAT | os.O_EXCL | os.O_RDWR | getattr(os, "O_BINARY", 0))
        with os.fdopen(fd, 'rb+') as tar_file:
            tar_file.truncate()
            self.generateTarball(tar_file)
            logger.debug('generated tar file of length %s', tar_file.tell())
            tar_file.seek(0)
            # calculate the hash of the file before we upload it:
            shasum = hashlib.sha256()
            while True:
                chunk = tar_file.read(1000)
                if not chunk:
                    break
                shasum.update(chunk)
            logger.debug('generated tar file has hash %s', shasum.hexdigest())
            tar_file.seek(0)
            with self.findAndOpenReadme() as readme_file_wrapper:
                if not readme_file_wrapper:
                    logger.warning("no readme.md file detected")
                with open(self.getDescriptionFile(), 'r') as description_file:
                    return registry_access.publish(
                        self.getRegistryNamespace(),
                        self.getName(),
                        self.getVersion(),
                        description_file,
                        tar_file,
                        readme_file_wrapper.file,
                        readme_file_wrapper.extension().lower(),
                        registry=registry
                    )


Instruction:
Here you have a function in Python 3, explain what it does
def unpublish(self, registry=None):
        ''' Try to un-publish the current version. Return a description of any
            errors that occured, or None if successful.
        '''
        return registry_access.unpublish(
            self.getRegistryNamespace(),
            self.getName(),
            self.getVersion(),
            registry=registry
        )

Response:
Try to un - publish the current version. Return a description of any
            errors that occured.


Instruction:
Can you generate the documentation for the following Python 3 function
def getScript(self, scriptname):
        ''' Return the specified script command. If the first part of the
            command is a .py file, then the current python interpreter is
            prepended.

            If the script is a single string, rather than an array, it is
            shlex-split.
        '''
        script = self.description.get('scripts', {}).get(scriptname, None)
        if script is not None:
            if isinstance(script, str) or isinstance(script, type(u'unicode string')):
                import shlex
                script = shlex.split(script)
            # if the command is a python script, run it with the python
            # interpreter being used to run yotta, also fetch the absolute path
            # to the script relative to this module (so that the script can be
            # distributed with the module, no matter what current working
            # directory it will be executed in):
            if len(script) and script[0].lower().endswith('.py'):
                if not os.path.isabs(script[0]):
                    absscript = os.path.abspath(os.path.join(self.path, script[0]))
                    logger.debug('rewriting script %s to be absolute path %s', script[0], absscript)
                    script[0] = absscript
                import sys
                script = [sys.executable] + script

        return script

Response: Return the specified script command.


Instruction:
Here you have a function in Python 3, explain what it does
def runScript(self, scriptname, additional_environment=None):
        ''' Run the specified script from the scripts section of the
            module.json file in the directory of this module.
        '''
        import subprocess
        import shlex

        command = self.getScript(scriptname)
        if command is None:
            logger.debug('%s has no script %s', self, scriptname)
            return 0

        if not len(command):
            logger.error("script %s of %s is empty", scriptname, self.getName())
            return 1

        # define additional environment variables for scripts:
        env = os.environ.copy()
        if additional_environment is not None:
            env.update(additional_environment)

        errcode = 0
        child = None
        try:
            logger.debug('running script: %s', command)
            child = subprocess.Popen(
                command, cwd = self.path, env = env
            )
            child.wait()
            if child.returncode:
                logger.error(
                    "script %s (from %s) exited with non-zero status %s",
                    scriptname,
                    self.getName(),
                    child.returncode
                )
                errcode = child.returncode
            child = None
        finally:
            if child is not None:
                tryTerminate(child)
        return errcode

Response: Runs the specified script in the scripts section of the current module. json file in the directory of this module.


Instruction:
Here you have a function in Python 3, explain what it does
def _truthyConfValue(v):
    ''' Determine yotta-config truthiness. In yotta config land truthiness is
        different to python or json truthiness (in order to map nicely only
        preprocessor and CMake definediness):

          json      -> python -> truthy/falsey
          false     -> False  -> Falsey
          null      -> None   -> Falsey
          undefined -> None   -> Falsey
          0         -> 0      -> Falsey
          ""        -> ""     -> Truthy (different from python)
          "0"       -> "0"    -> Truthy
          {}        -> {}     -> Truthy (different from python)
          []        -> []     -> Truthy (different from python)
          everything else is truthy
    '''
    if v is False:
        return False
    elif v is None:
        return False
    elif v == 0:
        return False
    else:
        # everything else is truthy!
        return True

Response: Determine whether the given value is truthy or not.


Instruction:
How would you code a function in Python 3 to
return a list of dependency specs for this component.

Response:
def getDependencySpecs(self, target=None):
        ''' Returns [DependencySpec]

            These are returned in the order that they are listed in the
            component description file: this is so that dependency resolution
            proceeds in a predictable way.
        '''
        deps = []

        def specForDependency(name, version_spec, istest):
            shrinkwrap = self.getShrinkwrapMapping()
            shrinkwrap_version_req = None
            if name in shrinkwrap:
                # exact version, and pull from registry:
                shrinkwrap_version_req = shrinkwrap[name]
                logger.debug(
                    'respecting %s shrinkwrap version %s for %s', self.getName(), shrinkwrap_version_req, name
                )
            return pack.DependencySpec(
                                         name,
                                         version_spec,
                                         istest,
                shrinkwrap_version_req = shrinkwrap_version_req,
                     specifying_module = self.getName()
            )

        deps += [specForDependency(x[0], x[1], False) for x in self.description.get('dependencies', {}).items()]
        target_deps = self.description.get('targetDependencies', {})
        if target is not None:
            for conf_key, target_conf_deps in target_deps.items():
                if _truthyConfValue(target.getConfigValue(conf_key)) or conf_key in target.getSimilarTo_Deprecated():
                    logger.debug(
                        'Adding target-dependent dependency specs for target config %s to component %s' %
                        (conf_key, self.getName())
                    )
                    deps += [specForDependency(x[0], x[1], False) for x in target_conf_deps.items()]

        deps += [specForDependency(x[0], x[1], True) for x in self.description.get('testDependencies', {}).items()]
        target_deps = self.description.get('testTargetDependencies', {})
        if target is not None:
            for conf_key, target_conf_deps in target_deps.items():
                if _truthyConfValue(target.getConfigValue(conf_key)) or conf_key in target.getSimilarTo_Deprecated():
                    logger.debug(
                        'Adding test-target-dependent dependency specs for target config %s to component %s' %
                        (conf_key, self.getName())
                    )
                    deps += [specForDependency(x[0], x[1], True) for x in target_conf_deps.items()]

        # remove duplicates (use the first occurrence)
        seen = set()
        r = []
        for dep in deps:
            if not dep.name in seen:
                r.append(dep)
                seen.add(dep.name)

        return r


Instruction:
Can you tell what is the following Python 3 function doing
def hasDependency(self, name, target=None, test_dependencies=False):
        ''' Check if this module has any dependencies with the specified name
            in its dependencies list, or in target dependencies for the
            specified target
        '''
        if name in self.description.get('dependencies', {}).keys():
            return True

        target_deps = self.description.get('targetDependencies', {})
        if target is not None:
            for conf_key, target_conf_deps in target_deps.items():
                if _truthyConfValue(target.getConfigValue(conf_key)) or conf_key in target.getSimilarTo_Deprecated():
                    if name in target_conf_deps:
                        return True

        if test_dependencies:
            if name in self.description.get('testDependencies', {}).keys():
                return True

            if target is not None:
                test_target_deps = self.description.get('testTargetDependencies', {})
                for conf_key, target_conf_deps in test_target_deps.items():
                    if _truthyConfValue(target.getConfigValue(conf_key)) or conf_key in target.getSimilarTo_Deprecated():
                        if name in target_conf_deps:
                            return True
        return False

Response:
Check if this module has any dependencies with the specified name
            in its dependencies list or in target dependencies for the specified target
           .


Instruction:
Can you implement a function in Python 3 that
checks if this module or any of its dependencies have the specified name in their targetDependencies corresponding to the specified target.

Response:
def hasDependencyRecursively(self, name, target=None, test_dependencies=False):
        ''' Check if this module, or any of its dependencies, have a
            dependencies with the specified name in their dependencies, or in
            their targetDependencies corresponding to the specified target.

            Note that if recursive dependencies are not installed, this test
            may return a false-negative.
        '''
        # checking dependencies recursively isn't entirely straightforward, so
        # use the existing method to resolve them all before checking:
        dependencies = self.getDependenciesRecursive(
                               target = target,
                                 test = test_dependencies
        )
        return (name in dependencies)


Instruction:
Make a summary of the following Python 3 code
def getDependencies(self,
        available_components = None,
                 search_dirs = None,
                      target = None,
              available_only = False,
                        test = False,
                    warnings = True
        ):
        ''' Returns {component_name:component}
        '''
        if search_dirs is None:
            search_dirs = [self.modulesPath()]
        available_components = self.ensureOrderedDict(available_components)

        components, errors = self.__getDependenciesWithProvider(
            available_components = available_components,
                     search_dirs = search_dirs,
                          target = target,
                update_installed = False,
                        provider = self.provideInstalled,
                            test = test
        )
        if warnings:
            for error in errors:
                logger.warning(error)
        if available_only:
            components = OrderedDict((k, v) for k, v in components.items() if v)
        return components

Response: Returns a dictionary of component_name - > component


Instruction:
Given the following Python 3 function, write the documentation
def __getDependenciesWithProvider(self,
                      available_components = None,
                               search_dirs = None,
                                    target = None,
                          update_installed = False,
                                  provider = None,
                                      test = False
   ):
        ''' Get installed components using "provider" to find (and possibly
            install) components.

            See documentation for __getDependenciesRecursiveWithProvider

            returns (components, errors)
        '''
        # sourceparse, , parse version source urls, internal
        from yotta.lib import sourceparse
        errors = []
        modules_path = self.modulesPath()
        def satisfyDep(dspec):
            try:
                r = provider(
                  dspec,
                  available_components,
                  search_dirs,
                  modules_path,
                  update_installed,
                  self
                )
                if r and not sourceparse.parseSourceURL(dspec.versionReq()).semanticSpecMatches(r.getVersion()):
                    shrinkwrap_msg = ''
                    if dspec.isShrinkwrapped():
                        shrinkwrap_msg = 'shrinkwrap on '
                    msg = 'does not meet specification %s required by %s%s' % (
                        dspec.versionReq(), shrinkwrap_msg, self.getName()
                    )
                    logger.debug('%s %s', r.getName(), msg)
                    r.setError(msg)
                return r
            except access_common.Unavailable as e:
                errors.append(e)
                self.dependencies_failed = True
            except vcs.VCSError as e:
                errors.append(e)
                self.dependencies_failed = True
        specs = self.getDependencySpecs(target=target)
        if not test:
            # filter out things that aren't test dependencies if necessary:
            specs = [x for x in specs if not x.is_test_dependency]
        #dependencies = pool.map(
        dependencies = map(
            satisfyDep, specs
        )
        self.installed_dependencies = True
        # stable order is important!
        return (OrderedDict([((d and d.getName()) or specs[i].name, d) for i, d in enumerate(dependencies)]), errors)

Response: Get installed components using the specified provider.


Instruction:
Given the following Python 3 function, write the documentation
def __getDependenciesRecursiveWithProvider(self,
                               available_components = None,
                                        search_dirs = None,
                                             target = None,
                                     traverse_links = False,
                                   update_installed = False,
                                           provider = None,
                                               test = False,
                                         _processed = None
    ):
        ''' Get installed components using "provider" to find (and possibly
            install) components.

            This function is called with different provider functions in order
            to retrieve a list of all of the dependencies, or install all
            dependencies.

            Returns
            =======
                (components, errors)

                components: dictionary of name:Component
                errors: sequence of errors

            Parameters
            ==========
                available_components:
                    None (default) or a dictionary of name:component. This is
                    searched before searching directories or fetching remote
                    components

                search_dirs:
                    None (default), or sequence of directories to search for
                    already installed, (but not yet loaded) components. Used so
                    that manually installed or linked components higher up the
                    dependency tree are found by their users lower down.

                    These directories are searched in order, and finally the
                    current directory is checked.

                target:
                    None (default), or a Target object. If specified the target
                    name and it's similarTo list will be used in resolving
                    dependencies. If None, then only target-independent
                    dependencies will be installed

                traverse_links:
                    False (default) or True: whether to recurse into linked
                    dependencies. You normally want to set this to "True" when
                    getting a list of dependencies, and False when installing
                    them (unless the user has explicitly asked dependencies to
                    be installed in linked components).

                provider: None (default) or function:
                          provider(
                            dependency_spec,
                            available_components,
                            search_dirs,
                            working_directory,
                            update_if_installed
                          )
                test:
                    True, False, 'toplevel': should test-only dependencies be
                    included (yes, no, or only at this level, not recursively)
        '''
        def recursionFilter(c):
            if not c:
                logger.debug('do not recurse into failed component')
                # don't recurse into failed components
                return False
            if c.getName() in _processed:
                logger.debug('do not recurse into already processed component: %s' % c)
                return False
            if c.installedLinked() and not traverse_links:
                return False
            return True
        available_components = self.ensureOrderedDict(available_components)
        if search_dirs is None:
            search_dirs = []
        if _processed is None:
            _processed = set()
        assert(test in [True, False, 'toplevel'])
        search_dirs.append(self.modulesPath())
        logger.debug('process %s\nsearch dirs:%s' % (self.getName(), search_dirs))
        if self.isTestDependency():
            logger.debug("won't provide test dependencies recursively for test dependency %s", self.getName())
            test = False
        components, errors = self.__getDependenciesWithProvider(
            available_components = available_components,
                     search_dirs = search_dirs,
                update_installed = update_installed,
                          target = target,
                        provider = provider,
                            test = test
        )
        _processed.add(self.getName())
        if errors:
            errors = ['Failed to satisfy dependencies of %s:' % self.path] + errors
        need_recursion = [x for x in filter(recursionFilter, components.values())]
        available_components.update(components)
        logger.debug('processed %s\nneed recursion: %s\navailable:%s\nsearch dirs:%s' % (self.getName(), need_recursion, available_components, search_dirs))
        if test == 'toplevel':
            test = False
        # NB: can't perform this step in parallel, since the available
        # components list must be updated in order
        for c in need_recursion:
            dep_components, dep_errors = c.__getDependenciesRecursiveWithProvider(
                available_components = available_components,
                         search_dirs = search_dirs,
                              target = target,
                      traverse_links = traverse_links,
                    update_installed = update_installed,
                            provider = provider,
                                test = test,
                          _processed = _processed
            )
            available_components.update(dep_components)
            components.update(dep_components)
            errors += dep_errors
        return (components, errors)

Response: This function returns a list of all of the dependencies that are recursively installed and installed.


Instruction:
Create a Python 3 function to
retrieve and install all the dependencies of this component and its dependents recursively or from disk.

Response:
def satisfyDependenciesRecursive(
                            self,
            available_components = None,
                     search_dirs = None,
                update_installed = False,
                  traverse_links = False,
                          target = None,
                            test = False
        ):
        ''' Retrieve and install all the dependencies of this component and its
            dependencies, recursively, or satisfy them from a collection of
            available_components or from disk.

            Returns
            =======
                (components, errors)

                components: dictionary of name:Component
                errors: sequence of errors

            Parameters
            ==========

                available_components:
                    None (default) or a dictionary of name:component. This is
                    searched before searching directories or fetching remote
                    components

                search_dirs:
                    None (default), or sequence of directories to search for
                    already installed, (but not yet loaded) components. Used so
                    that manually installed or linked components higher up the
                    dependency tree are found by their users lower down.

                    These directories are searched in order, and finally the
                    current directory is checked.

                update_installed:
                    False (default), True, or set(): whether to check the
                    available versions of installed components, and update if a
                    newer version is available. If this is a set(), only update
                    things in the specified set.

                traverse_links:
                    False (default) or True: whether to recurse into linked
                    dependencies when updating/installing.

                target:
                    None (default), or a Target object. If specified the target
                    name and it's similarTo list will be used in resolving
                    dependencies. If None, then only target-independent
                    dependencies will be installed

                test:
                    True, False, or 'toplevel: should test-only dependencies be
                    installed? (yes, no, or only for this module, not its
                    dependencies).

        '''
        def provider(
            dspec,
            available_components,
            search_dirs,
            working_directory,
            update_installed,
            dep_of=None
        ):
            r = access.satisfyFromAvailable(dspec.name, available_components)
            if r:
                if r.isTestDependency() and not dspec.is_test_dependency:
                    logger.debug('test dependency subsequently occurred as real dependency: %s', r.getName())
                    r.setTestDependency(False)
                return r
            update_if_installed = False
            if update_installed is True:
                update_if_installed = True
            elif update_installed:
                update_if_installed = dspec.name in update_installed
            r = access.satisfyVersionFromSearchPaths(
                dspec.name,
                dspec.versionReq(),
                search_dirs,
                update_if_installed,
                inherit_shrinkwrap = dep_of.getShrinkwrap()
            )
            if r:
                r.setTestDependency(dspec.is_test_dependency)
                return r
            # before resorting to install this module, check if we have an
            # existing linked module (which wasn't picked up because it didn't
            # match the version specification) - if we do, then we shouldn't
            # try to install, but should return that anyway:
            default_path = os.path.join(self.modulesPath(), dspec.name)
            if fsutils.isLink(default_path):
                r = Component(
                                       default_path,
                     test_dependency = dspec.is_test_dependency,
                    installed_linked = fsutils.isLink(default_path),
                  inherit_shrinkwrap = dep_of.getShrinkwrap()
                )
                if r:
                    assert(r.installedLinked())
                    return r
                else:
                    logger.error('linked module %s is invalid: %s', dspec.name, r.getError())
                    return r

            r = access.satisfyVersionByInstalling(
                dspec.name,
                dspec.versionReq(),
                self.modulesPath(),
                inherit_shrinkwrap = dep_of.getShrinkwrap()
            )
            if not r:
                logger.error('could not install %s' % dspec.name)
            if r is not None:
                r.setTestDependency(dspec.is_test_dependency)
            return r

        return self.__getDependenciesRecursiveWithProvider(
           available_components = available_components,
                    search_dirs = search_dirs,
                         target = target,
                 traverse_links = traverse_links,
               update_installed = update_installed,
                       provider = provider,
                           test = test
        )


Instruction:
How would you explain what the following Python 3 function does
def satisfyTarget(self, target_name_and_version, update_installed=False, additional_config=None, install_missing=True):
        ''' Ensure that the specified target name (and optionally version,
            github ref or URL) is installed in the targets directory of the
            current component

            returns (derived_target, errors)
        '''
        # Target, , represent an installed target, internal
        from yotta.lib import target
        application_dir = None
        if self.isApplication():
            application_dir = self.path
        return target.getDerivedTarget(
                                target_name_and_version,
                                self.targetsPath(),
              install_missing = install_missing,
              application_dir = application_dir,
             update_installed = update_installed,
            additional_config = additional_config,
                   shrinkwrap = self.getShrinkwrap()
        )

Response:
Ensure that the specified target name and version is installed in the targets directory of the current component
            returns a derived target object.


Instruction:
Given the following Python 3 function, write the documentation
def getTarget(self, target_name_and_version, additional_config=None):
        ''' Return a derived target object representing the selected target: if
            the target is not installed, or is invalid then the returned object
            will test false in a boolean context.

            Returns derived_target

            Errors are not displayed.
        '''
        derived_target, errors = self.satisfyTarget(
                               target_name_and_version,
           additional_config = additional_config,
             install_missing = False
        )
        if len(errors):
            return None
        else:
            return derived_target

Response: Returns a derived target object representing the selected target.