* bpo-15987: Implement ast.compare
Add a compare() function that compares two ASTs for structural equality. There are two set of attributes on AST node objects, fields and attributes. The fields are always compared, since they represent the actual structure of the code. The attributes can be optionally be included in the comparison. Attributes capture things like line numbers of column offsets, so comparing them involves test whether the layout of the program text is the same. Since whitespace seems inessential for comparing ASTs, the default is to compare fields but not attributes.
ASTs are just Python objects that can be modified in arbitrary ways. The API for ASTs is under-specified in the presence of user modifications to objects. The comparison respects modifications to fields and attributes, and to _fields and _attributes attributes. A user could create obviously malformed objects, and the code will probably fail with an AttributeError when that happens. (For example, adding "spam" to _fields but not adding a "spam" attribute to the object.)
Co-authored-by: Jeremy Hylton <jeremy@alum.mit.edu>
This implements PEP 695, Type Parameter Syntax. It adds support for:
- Generic functions (def func[T](): ...)
- Generic classes (class X[T](): ...)
- Type aliases (type X = ...)
- New scoping when the new syntax is used within a class body
- Compiler and interpreter changes to support the new syntax and scoping rules
Co-authored-by: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Co-authored-by: Eric Traut <eric@traut.com>
Co-authored-by: Larry Hastings <larry@hastings.org>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
`ast.Num`, `ast.Str`, `ast.Bytes`, `ast.Ellipsis` and `ast.NameConstant` now all emit deprecation warnings on import, access, instantation or `isinstance()` checks.
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
This doesn't happen naturally, but is allowed by the ASDL and compiler.
We don't want to change ASDL for backward compatibility reasons
(#57645, #92987)
add:
* `_simple_enum` decorator to transform a normal class into an enum
* `_test_simple_enum` function to compare
* `_old_convert_` to enable checking `_convert_` generated enums
`_simple_enum` takes a normal class and converts it into an enum:
@simple_enum(Enum)
class Color:
RED = 1
GREEN = 2
BLUE = 3
`_old_convert_` works much like` _convert_` does, using the original logic:
# in a test file
import socket, enum
CheckedAddressFamily = enum._old_convert_(
enum.IntEnum, 'AddressFamily', 'socket',
lambda C: C.isupper() and C.startswith('AF_'),
source=_socket,
)
`_test_simple_enum` takes a traditional enum and a simple enum and
compares the two:
# in the REPL or the same module as Color
class CheckedColor(Enum):
RED = 1
GREEN = 2
BLUE = 3
_test_simple_enum(CheckedColor, Color)
_test_simple_enum(CheckedAddressFamily, socket.AddressFamily)
Any important differences will raise a TypeError
add:
_simple_enum decorator to transform a normal class into an enum
_test_simple_enum function to compare
_old_convert_ to enable checking _convert_ generated enums
_simple_enum takes a normal class and converts it into an enum:
@simple_enum(Enum)
class Color:
RED = 1
GREEN = 2
BLUE = 3
_old_convert_ works much like _convert_ does, using the original logic:
# in a test file
import socket, enum
CheckedAddressFamily = enum._old_convert_(
enum.IntEnum, 'AddressFamily', 'socket',
lambda C: C.isupper() and C.startswith('AF_'),
source=_socket,
)
test_simple_enum takes a traditional enum and a simple enum and
compares the two:
# in the REPL or the same module as Color
class CheckedColor(Enum):
RED = 1
GREEN = 2
BLUE = 3
_test_simple_enum(CheckedColor, Color)
_test_simple_enum(CheckedAddressFamily, socket.AddressFamily)
Any important differences will raise a TypeError
By attempting to avoid backslashes in f-string expressions.
We also now proactively raise errors for some backslashes we can't
avoid while unparsing FormattedValues
Co-authored-by: hauntsaninja <>
Co-authored-by: Shantanu <hauntsaninja@users.noreply.github.com>
Co-authored-by: Batuhan Taskaya <isidentical@gmail.com>
Partially revert commit ac46eb4ad6662cf6d771b20d8963658b2186c48c:
"bpo-38113: Update the Python-ast.c generator to PEP384 (gh-15957)".
Using a module state per module instance is causing subtle practical
problems.
For example, the Mercurial project replaces the __import__() function
to implement lazy import, whereas Python expected that "import _ast"
always return a fully initialized _ast module.
Add _PyAST_Fini() to clear the state at exit.
The _ast module has no state (set _astmodule.m_size to 0). Remove
astmodule_traverse(), astmodule_clear() and astmodule_free()
functions.
When unparsing a non-empty tuple, the parentheses can be safely
omitted if there aren't any elements that explicitly require them (such as starred expressions).
Unprintable characters such as `\x00` weren't correctly roundtripped
due to not using default string repr when generating docstrings. This
patch correctly encodes all unprintable characters (except `\n` and `\t`, which
are commonly used for formatting, and found unescaped).
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
Co-authored-by: Batuhan Taskaya <isidentical@gmail.com>
Bénédikt Tran
Jelle Zijlstra
Alex Waygood
Batuhan Taskaya
Nikita Sobolev
Frank Hoffmann
Shantanu
Serhiy Storchaka
Pablo Galindo Salgado
Anthony Shaw
Irit Katriel
Tian Gao
Gregory P. Smith
Anthony Sottile
Matthew Rahtz
Binbin
Ikko Ashimine
Nick Coghlan
Ethan Furman
Kodi Arfer
Brandt Bucher
Irit Katriel
Batuhan Taskaya
Victor Stinner
Rémi Lapeyre
CyberSaxosTiGER