diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS index bd199f8168b..11e8acd963a 100644 --- a/.github/CODEOWNERS +++ b/.github/CODEOWNERS @@ -320,3 +320,9 @@ Lib/test/test__colorize.py @hugovk # Fuzzing Modules/_xxtestfuzz/ @ammaraskar + +# t-strings +**/*interpolationobject* @lysnikolaou +**/*templateobject* @lysnikolaou +**/*templatelib* @lysnikolaou +**/*tstring* @lysnikolaou diff --git a/Doc/library/token.rst b/Doc/library/token.rst index 24455b1ef77..1529d173e17 100644 --- a/Doc/library/token.rst +++ b/Doc/library/token.rst @@ -131,6 +131,41 @@ The token constants are: The token string contains the closing quote(s). +.. data:: TSTRING_START + + Token value used to indicate the beginning of a template string literal. + + .. impl-detail:: + + The token string includes the prefix and the opening quote(s), but none + of the contents of the literal. + + .. versionadded:: next + +.. data:: TSTRING_MIDDLE + + Token value used for literal text inside a template string literal + including format specifications. + + .. impl-detail:: + + Replacement fields (that is, the non-literal parts of t-strings) use + the same tokens as other expressions, and are delimited by + :data:`LBRACE`, :data:`RBRACE`, :data:`EXCLAMATION` and :data:`COLON` + tokens. + + .. versionadded:: next + +.. data:: TSTRING_END + + Token value used to indicate the end of a template string literal. + + .. impl-detail:: + + The token string contains the closing quote(s). + + .. versionadded:: next + .. data:: ENDMARKER Token value that indicates the end of input. diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst index 9e6b69fbc05..dad63e47a62 100644 --- a/Doc/whatsnew/3.14.rst +++ b/Doc/whatsnew/3.14.rst @@ -66,6 +66,7 @@ Summary -- release highlights * :ref:`PEP 649: deferred evaluation of annotations ` * :ref:`PEP 741: Python Configuration C API ` +* :ref:`PEP 750: Template Strings ` * :ref:`PEP 758: Allow except and except* expressions without parentheses ` * :ref:`PEP 761: Discontinuation of PGP signatures ` * :ref:`PEP 765: Disallow return/break/continue that exit a finally block ` @@ -92,6 +93,76 @@ If you encounter :exc:`NameError`\s or pickling errors coming out of New features ============ +.. _whatsnew314-pep750: + +PEP 750: Template Strings +------------------------- + +Template string literals (t-strings) are a generalization of f-strings, +using a ``t`` in place of the ``f`` prefix. Instead of evaluating +to :class:`str`, t-strings evaluate to a new :class:`!string.templatelib.Template` type: + +.. code-block:: python + + from string.templatelib import Template + + name = "World" + template: Template = t"Hello {name}" + +The template can then be combined with functions that operate on the template's +structure to produce a :class:`str` or a string-like result. +For example, sanitizing input: + +.. code-block:: python + + evil = "" + template = t"

{evil}

" + assert html(template) == "

<script>alert('evil')</script>

" + +As another example, generating HTML attributes from data: + +.. code-block:: python + + attributes = {"src": "shrubbery.jpg", "alt": "looks nice"} + template = t"" + assert html(template) == 'looks nice' + +Unlike f-strings, the ``html`` function has access to template attributes +containing the original information: static strings, interpolations, and values +from the original scope. Unlike existing templating approaches, t-strings build +from the well-known f-string syntax and rules. Template systems thus benefit +from Python tooling as they are much closer to the Python language, syntax, +scoping, and more. + +Writing template handlers is straightforward: + +.. code-block:: python + + from string.templatelib import Template, Interpolation + + def lower_upper(template: Template) -> str: + """Render static parts lowercased and interpolations uppercased.""" + parts: list[str] = [] + for item in template: + if isinstance(item, Interpolation): + parts.append(str(item.value).upper()) + else: + parts.append(item.lower()) + return "".join(parts) + + name = "world" + assert lower_upper(t"HELLO {name}") == "hello WORLD" + +With this in place, developers can write template systems to sanitize SQL, make +safe shell operations, improve logging, tackle modern ideas in web development +(HTML, CSS, and so on), and implement lightweight, custom business DSLs. + +See :pep:`750` for more details. + +(Contributed by Jim Baker, Guido van Rossum, Paul Everitt, Koudai Aono, +Lysandros Nikolaou, Dave Peck, Adam Turner, Jelle Zijlstra, Bénédikt Tran, +and Pablo Galindo Salgado in :gh:`132661`.) + .. _whatsnew314-pep768: PEP 768: Safe external debugger interface for CPython diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-04-22-15-37-05.gh-issue-132661.XE_A42.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-04-22-15-37-05.gh-issue-132661.XE_A42.rst new file mode 100644 index 00000000000..666e8de943b --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-04-22-15-37-05.gh-issue-132661.XE_A42.rst @@ -0,0 +1,3 @@ +Implement :pep:`750` (Template Strings). Add new syntax for t-strings and +implement new internal :class:`!string.templatelib.Template` and +:class:`!string.templatelib.Interpolation` types. diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj index 59d664dc174..1f3f3170f3f 100644 --- a/PCbuild/_freeze_module.vcxproj +++ b/PCbuild/_freeze_module.vcxproj @@ -143,6 +143,7 @@  + @@ -158,6 +159,7 @@  + diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj index ce9b056ac25..d2aafce058d 100644 --- a/PCbuild/pythoncore.vcxproj +++ b/PCbuild/pythoncore.vcxproj @@ -264,6 +264,7 @@  + @@ -310,6 +311,7 @@  + @@ -528,6 +530,7 @@  + @@ -543,6 +546,7 @@  + diff --git a/PCbuild/pythoncore.vcxproj.filters b/PCbuild/pythoncore.vcxproj.filters index 2c2eac85941..873f7d65a26 100644 --- a/PCbuild/pythoncore.vcxproj.filters +++ b/PCbuild/pythoncore.vcxproj.filters @@ -708,6 +708,9 @@  Include\internal + + Include\internal + Include\cpython @@ -840,6 +843,9 @@  Include\internal + + Include\internal + Include\internal diff --git a/Programs/test_frozenmain.h b/Programs/test_frozenmain.h index 8cedee31e08..b7d23f57018 100644 --- a/Programs/test_frozenmain.h +++ b/Programs/test_frozenmain.h @@ -1,19 +1,19 @@ // Auto-generated by Programs/freeze_test_frozenmain.py unsigned char M_test_frozenmain[] = { 227,0,0,0,0,0,0,0,0,0,0,0,0,8,0,0, - 0,0,0,0,0,243,184,0,0,0,128,0,92,0,80,1, - 71,0,114,0,92,0,80,1,71,1,114,1,91,2,32,0, - 80,2,50,1,0,0,0,0,0,0,30,0,91,2,32,0, - 80,3,91,0,78,6,0,0,0,0,0,0,0,0,0,0, - 0,0,0,0,0,0,0,0,50,2,0,0,0,0,0,0, - 30,0,91,1,78,8,0,0,0,0,0,0,0,0,0,0, - 0,0,0,0,0,0,0,0,32,0,50,0,0,0,0,0, - 0,0,80,4,43,26,0,0,0,0,0,0,0,0,0,0, - 114,5,80,7,15,0,68,24,0,0,114,6,91,2,32,0, - 80,5,91,6,11,0,80,6,91,5,91,6,43,26,0,0, - 0,0,0,0,0,0,0,0,11,0,48,4,50,1,0,0, - 0,0,0,0,30,0,73,26,0,0,8,0,29,0,80,1, - 34,0,41,8,233,0,0,0,0,78,122,18,70,114,111,122, + 0,0,0,0,0,243,184,0,0,0,128,0,94,0,82,1, + 73,0,116,0,94,0,82,1,73,1,116,1,93,2,33,0, + 82,2,52,1,0,0,0,0,0,0,31,0,93,2,33,0, + 82,3,93,0,80,6,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,52,2,0,0,0,0,0,0, + 31,0,93,1,80,8,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,33,0,52,0,0,0,0,0, + 0,0,82,4,44,26,0,0,0,0,0,0,0,0,0,0, + 116,5,82,7,16,0,70,24,0,0,116,6,93,2,33,0, + 82,5,93,6,12,0,82,6,93,5,93,6,44,26,0,0, + 0,0,0,0,0,0,0,0,12,0,50,4,52,1,0,0, + 0,0,0,0,31,0,75,26,0,0,9,0,30,0,82,1, + 35,0,41,8,233,0,0,0,0,78,122,18,70,114,111,122, 101,110,32,72,101,108,108,111,32,87,111,114,108,100,122,8, 115,121,115,46,97,114,103,118,218,6,99,111,110,102,105,103, 122,7,99,111,110,102,105,103,32,122,2,58,32,41,5,218, diff --git a/Tools/c-analyzer/TODO b/Tools/c-analyzer/TODO index d509489176b..2077534ccf4 100644 --- a/Tools/c-analyzer/TODO +++ b/Tools/c-analyzer/TODO @@ -794,6 +794,7 @@ Objects/genobject.c:_PyAsyncGenASend_Type PyTypeObject _P Objects/genobject.c:_PyAsyncGenAThrow_Type PyTypeObject _PyAsyncGenAThrow_Type Objects/genobject.c:_PyAsyncGenWrappedValue_Type PyTypeObject _PyAsyncGenWrappedValue_Type Objects/genobject.c:_PyCoroWrapper_Type PyTypeObject _PyCoroWrapper_Type +Objects/interpolationobject.c:_PyInterpolation_Type PyTypeObject _PyInterpolation_Type Objects/interpreteridobject.c:_PyInterpreterID_Type PyTypeObject _PyInterpreterID_Type Objects/iterobject.c:PyCallIter_Type PyTypeObject PyCallIter_Type Objects/iterobject.c:PySeqIter_Type PyTypeObject PySeqIter_Type @@ -827,6 +828,8 @@ Objects/sliceobject.c:PyEllipsis_Type PyTypeObject Py Objects/sliceobject.c:PySlice_Type PyTypeObject PySlice_Type Objects/stringlib/unicode_format.h:PyFieldNameIter_Type static PyTypeObject PyFieldNameIter_Type Objects/stringlib/unicode_format.h:PyFormatterIter_Type static PyTypeObject PyFormatterIter_Type +Objects/templateobject.c:_PyTemplateIter_Type PyTypeObject _PyTemplateIter_Type +Objects/templateobject.c:_PyTemplate_Type PyTypeObject _PyTemplate_Type Objects/tupleobject.c:PyTupleIter_Type PyTypeObject PyTupleIter_Type Objects/tupleobject.c:PyTuple_Type PyTypeObject PyTuple_Type Objects/typeobject.c:PyBaseObject_Type PyTypeObject PyBaseObject_Type