File size: 4,835 Bytes
f5fb003 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 | """This is an implementation of functions that interact with the tzdata module.
It will only live as long as :mod:`dateutil.zoneinfo` lives; when the
``dateutil.zoneinfo`` module is removed, this can all move under :mod:`tz`.
"""
import contextlib
import importlib
import io
import os
import pkgutil
import sys
import six
if six.PY2:
_TZDATA_LOAD_EXCEPTIONS = (
ImportError,
IOError,
UnicodeEncodeError,
ValueError,
)
else:
_TZDATA_LOAD_EXCEPTIONS = (
ImportError,
FileNotFoundError,
UnicodeEncodeError,
IsADirectoryError,
ValueError,
)
if sys.version_info < (3, 8):
_nullcontext = getattr(contextlib, "nullcontext", None)
if _nullcontext is None:
@contextlib.contextmanager
def _nullcontext(v):
yield v
def _get_data(package, resource):
# pkgutil.get_data returns None rather than raising when the package
# cannot be found (and on Python 2 raises AttributeError if the
# package has been blocked by setting sys.modules[name] = None), so
# import the package first to get the ImportError the callers expect
# from the importlib.resources versions of these functions.
importlib.import_module(package)
pkg_data = pkgutil.get_data(package, resource)
if pkg_data is None:
raise ImportError("No package named %r" % package)
return pkg_data
def _open_text(package, resource):
str_package_data = _get_data(package, resource).decode("utf-8")
return _nullcontext(io.StringIO(str_package_data))
def _open_binary(package, resource):
return io.BytesIO(_get_data(package, resource))
else:
import importlib.resources
if sys.version_info >= (3, 9):
def _open_text(package, resource):
return (
importlib.resources.files(package)
.joinpath(resource)
.open("r", encoding="utf-8")
)
def _open_binary(package, resource):
return (
importlib.resources.files(package).joinpath(resource).open("rb")
)
else:
_open_text = importlib.resources.open_text
_open_binary = importlib.resources.open_binary
def _is_package_directory(package, resource):
"""Whether ``resource`` names a directory inside ``package``.
Opening a directory raises IsADirectoryError on POSIX but PermissionError
on Windows, and on Python < 3.9 there is no portable way to ask the
resource API, so check the package's search path directly (the tzdata
package is a regular directory-backed package).
"""
try:
pkg = importlib.import_module(package)
except ImportError:
return False
for base in getattr(pkg, "__path__", ()):
if os.path.isdir(os.path.join(base, resource)):
return True
return False
def _load_tzdata(key):
components = key.split("/")
package_name = ".".join(["tzdata.zoneinfo"] + components[:-1])
resource_name = components[-1]
# Empty or relative path components cannot name a zone, and they produce
# module names that the import machinery handles inconsistently across
# versions, so treat them as not found up front. A key naming a directory
# (a subpackage) is not a zone either, and opening it raises a
# platform-dependent error, see CPython gh-85702.
if any(c in ("", ".", "..") for c in components) or _is_package_directory(
package_name, resource_name
):
raise TZFileNotFound("Time zone not found: %s", zone_key=key)
try:
return _open_binary(package_name, resource_name)
except _TZDATA_LOAD_EXCEPTIONS:
# ImportError: package does not exist (or tzdata is not installed)
# FileNotFoundError: the key is not a file in the package
# UnicodeEncodeError: the key is not encodable as a filename
# IsADirectoryError: the key names a package rather than a resource
# ValueError: the key is not a valid path (e.g. contains a NUL byte)
six.raise_from(
TZFileNotFound("Time zone not found: %s", zone_key=key), None
)
def _load_tzdata_keys():
with _open_text("tzdata", "zones") as f:
return list(filter(None, (l.strip() for l in f)))
class TZFileNotFound(ValueError):
"""Indicates that a time zone file isn't present in tzdata."""
def __init__(self, msg, *args, **kwargs):
# TODO: Use keyword-only argument when this is Python 3-only
zone_key = kwargs.pop("zone_key", None)
if zone_key is None: # pragma: nocover
raise TypeError("Required keyword argument missing: zone_key")
super(TZFileNotFound, self).__init__(msg % zone_key, *args)
self.zone_key = zone_key
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