cpython/PC
Emily Morehouse 8f59ee01be
bpo-35224: PEP 572 Implementation (#10497)
* Add tokenization of :=
- Add token to Include/token.h. Add token to documentation in Doc/library/token.rst.
- Run `./python Lib/token.py` to regenerate Lib/token.py.
- Update Parser/tokenizer.c: add case to handle `:=`.

* Add initial usage of := in grammar.

* Update Python.asdl to match the grammar updates. Regenerated Include/Python-ast.h and Python/Python-ast.c

* Update AST and compiler files in Python/ast.c and Python/compile.c. Basic functionality, this isn't scoped properly

* Regenerate Lib/symbol.py using `./python Lib/symbol.py`

* Tests - Fix failing tests in test_parser.py due to changes in token numbers for internal representation

* Tests - Add simple test for := token

* Tests - Add simple tests for named expressions using expr and suite

* Tests - Update number of levels for nested expressions to prevent stack overflow

* Update symbol table to handle NamedExpr

* Update Grammar to allow assignment expressions in if statements.
Regenerate Python/graminit.c accordingly using `make regen-grammar`

* Tests - Add additional tests for named expressions in RoundtripLegalSyntaxTestCase, based on examples and information directly from PEP 572

Note: failing tests are currently commented out (4 out of 24 tests currently fail)

* Tests - Add temporary syntax test failure tests in test_parser.py

Note: There is an outstanding TODO for this -- syntax tests need to be
moved to a different file (presumably test_syntax.py), but this is
covering what needs to be tested at the moment, and it's more convenient
to run a single test for the time being

* Add support for allowing assignment expressions as function argument annotations. Uncomment tests for these cases because they all pass now!

* Tests - Move existing syntax tests out of test_parser.py and into test_named_expressions.py. Refactor syntax tests to use unittest

* Add TargetScopeError exception to extend SyntaxError

Note: This simply creates the TargetScopeError exception, it is not yet
used anywhere

* Tests - Update tests per PEP 572

Continue refactoring test suite:
The named expression test suite now checks for any invalid cases that
throw exceptions (no longer limited to SyntaxErrors), assignment tests
to ensure that variables are properly assigned, and scope tests to
ensure that variable availability and values are correct

Note:
- There are still tests that are marked to skip, as they are not yet
implemented
- There are approximately 300 lines of the PEP that have not yet been
addressed, though these may be deferred

* Documentation - Small updates to XXX/todo comments

- Remove XXX from child description in ast.c
- Add comment with number of previously supported nested expressions for
3.7.X in test_parser.py

* Fix assert in seq_for_testlist()

* Cleanup - Denote "Not implemented -- No keyword args" on failing test case. Fix PEP8 error for blank lines at beginning of test classes in test_parser.py

* Tests - Wrap all file opens in `with...as` to ensure files are closed

* WIP: handle f(a := 1)

* Tests and Cleanup - No longer skips keyword arg test. Keyword arg test now uses a simpler test case and does not rely on an external file. Remove print statements from ast.c

* Tests - Refactor last remaining test case that relied on on external file to use a simpler test case without the dependency

* Tests - Add better description of remaning skipped tests. Add test checking scope when using assignment expression in a function argument

* Tests - Add test for nested comprehension, testing value and scope. Fix variable name in skipped comprehension scope test

* Handle restriction of LHS for named expressions - can only assign to LHS of type NAME. Specifically, restrict assignment to tuples

This adds an alternative set_context specifically for named expressions,
set_namedexpr_context. Thus, context is now set differently for standard
assignment versus assignment for named expressions in order to handle
restrictions.

* Tests - Update negative test case for assigning to lambda to match new error message. Add negative test case for assigning to tuple

* Tests - Reorder test cases to group invalid syntax cases and named assignment target errors

* Tests - Update test case for named expression in function argument - check that result and variable are set correctly

* Todo - Add todo for TargetScopeError based on Guido's comment (2b3acd37bd (r30472562))

* Tests - Add named expression tests for assignment operator in function arguments

Note: One of two tests are skipped, as function arguments are currently treating
an assignment expression inside of parenthesis as one child, which does
not properly catch the named expression, nor does it count arguments
properly

* Add NamedStore to expr_context. Regenerate related code with `make regen-ast`

* Add usage of NamedStore to ast_for_named_expr in ast.c. Update occurances of checking for Store to also handle NamedStore where appropriate

* Add ste_comprehension to _symtable_entry to track if the namespace is a comprehension. Initialize ste_comprehension to 0. Set set_comprehension to 1 in symtable_handle_comprehension

* s/symtable_add_def/symtable_add_def_helper. Add symtable_add_def to handle grabbing st->st_cur and passing it to symtable_add_def_helper. This now allows us to call the original code from symtable_add_def by instead calling symtable_add_def_helper with a different ste.

* Refactor symtable_record_directive to take lineno and col_offset as arguments instead of stmt_ty. This allows symtable_record_directive to be used for stmt_ty and expr_ty

* Handle elevating scope for named expressions in comprehensions.

* Handle error for usage of named expression inside a class block

* Tests - No longer skip scope tests. Add additional scope tests

* Cleanup - Update error message for named expression within a comprehension within a class. Update comments. Add assert for symtable_extend_namedexpr_scope to validate that we always find at least a ModuleScope if we don't find a Class or FunctionScope

* Cleanup - Add missing case for NamedStore in expr_context_name. Remove unused var in set_namedexpr_content

* Refactor - Consolidate set_context and set_namedexpr_context to reduce duplicated code. Special cases for named expressions are handled by checking if ctx is NamedStore

* Cleanup - Add additional use cases for ast_for_namedexpr in usage comment. Fix multiple blank lines in test_named_expressions

* Tests - Remove unnecessary test case. Renumber test case function names

* Remove TargetScopeError for now. Will add back if needed

* Cleanup - Small comment nit for consistency

* Handle positional argument check with named expression

* Add TargetScopeError exception definition. Add documentation for TargetScopeError in c-api docs. Throw TargetScopeError instead of SyntaxError when using a named expression in a comprehension within a class scope

* Increase stack size for parser by 200. This is a minimal change (approx. 5kb) and should not have an impact on any systems. Update parser test to allow 99 nested levels again

* Add TargetScopeError to exception_hierarchy.txt for test_baseexception.py_

* Tests - Major update for named expression tests, both in test_named_expressions and test_parser

- Add test for TargetScopeError
- Add tests for named expressions in comprehension scope and edge cases
- Add tests for named expressions in function arguments (declarations
and call sites)
- Reorganize tests to group them more logically

* Cleanup - Remove unnecessary comment

* Cleanup - Comment nitpicks

* Explicitly disallow assignment expressions to a name inside parentheses, e.g.: ((x) := 0)

- Add check for LHS types to detect a parenthesis then a name (see note)
- Add test for this scenario
- Update tests for changed error message for named assignment to a tuple
(also, see note)

Note: This caused issues with the previous error handling for named assignment
to a LHS that contained an expression, such as a tuple. Thus, the check
for the LHS of a named expression must be changed to be more specific if
we wish to maintain the previous error messages

* Cleanup - Wrap lines more strictly in test file

* Revert "Explicitly disallow assignment expressions to a name inside parentheses, e.g.: ((x) := 0)"

This reverts commit f1531400ca7d7a2d148830c8ac703f041740896d.

* Add NEWS.d entry

* Tests - Fix error in test_pickle.test_exceptions by adding TargetScopeError to list of exceptions

* Tests - Update error message tests to reflect improved messaging convention (s/can't/cannot)

* Remove cases that cannot be reached in compile.c. Small linting update.

* Update Grammar/Tokens to add COLONEQUAL. Regenerate all files

* Update TargetScopeError PRE_INIT and POST_INIT, as this was purposefully left out when fixing rebase conflicts

* Add NamedStore back and regenerate files

* Pass along line number and end col info for named expression

* Simplify News entry

* Fix compiler warning and explicity mark fallthrough
2019-01-24 16:49:56 -07:00
..
bdist_wininst bpo-33012: Fix invalid function cast warnings with gcc 8 for METH_NOARGS. (GH-6030) 2018-04-29 21:59:33 +03:00
clinic bpo-35582: Argument Clinic: inline parsing code for positional parameters. (GH-11313) 2019-01-11 16:01:14 +02:00
icons bpo-34977: Add Windows App Store package (GH-11027) 2018-12-10 18:52:57 -08:00
layout bpo-35683: Improve Azure Pipelines steps (GH-11493) 2019-01-22 10:49:52 -08:00
_msi.c bpo-23855: Add missing NULL checks for malloc() in _msi.c (GH-9038) 2018-09-08 01:02:56 +03:00
_testconsole.c bpo-31462: Remove trailing whitespaces. (#3564) 2017-09-14 09:38:36 +03:00
classicAppCompat.can.xml bpo-34977: Add Windows App Store package (GH-11027) 2018-12-10 18:52:57 -08:00
classicAppCompat.cat bpo-34977: Add Windows App Store package (GH-11027) 2018-12-10 18:52:57 -08:00
classicAppCompat.sccd bpo-34977: Add Windows App Store package (GH-11027) 2018-12-10 18:52:57 -08:00
config.c bpo-25711: Rewrite zipimport in pure Python. (GH-6809) 2018-09-18 22:22:29 +03:00
dl_nt.c Fixes sys.winver generation and removes dependency on user32.dll 2015-01-15 09:10:16 -08:00
empty.c
errmap.h Issue #13063: the Windows error ERROR_NO_DATA (numbered 232 and described 2011-10-07 16:16:31 +02:00
errmap.mak
frozen_dllmain.c Use GetModuleHandleW to avoid *A functions where possible. 2012-01-14 17:54:09 +01:00
generrmap.c Issue #13063: the Windows error ERROR_NO_DATA (numbered 232 and described 2011-10-07 16:16:31 +02:00
getpathp.c bpo-34977: Use venv redirector instead of original python.exe on Windows (GH-11029) 2018-12-10 08:11:21 -08:00
invalid_parameter_handler.c Issue #23524: Replace _PyVerify_fd function with calls to _set_thread_local_invalid_parameter_handler. 2015-04-12 00:26:27 -04:00
launcher.c bpo-34977: Use venv redirector instead of original python.exe on Windows (GH-11029) 2018-12-10 08:11:21 -08:00
msvcrtmodule.c bpo-31462: Remove trailing whitespaces. (#3564) 2017-09-14 09:38:36 +03:00
pyconfig.h bpo-11566: Extension build errors on Windows for _hypot (GH-11283) 2018-12-22 10:37:59 +09:00
pylauncher.rc bpo-34977: Add Windows App Store package (GH-11027) 2018-12-10 18:52:57 -08:00
pyshellext.cpp bpo-34770: Fix a possible null pointer dereference in pyshellext.cpp (GH-9497) 2018-09-24 21:25:23 -07:00
pyshellext.def Issue #27469: Adds a shell extension to the launcher so that drag and drop works correctly. 2016-07-16 16:17:33 -07:00
pyshellext.idl Issue #27469: Adds a shell extension to the launcher so that drag and drop works correctly. 2016-07-16 16:17:33 -07:00
pyshellext.rc Issue #27469: Adds a shell extension to the launcher so that drag and drop works correctly. 2016-07-16 16:17:33 -07:00
pyshellext_d.def Issue #27469: Adds a shell extension to the launcher so that drag and drop works correctly. 2016-07-16 16:17:33 -07:00
python.manifest bpo-30731: python.manifest fix (#2328) 2017-07-13 21:34:42 +02:00
python3.def bpo-35224: PEP 572 Implementation (#10497) 2019-01-24 16:49:56 -07:00
python3dll.c Add updated .hgeol file and fix newlines in the 3.2 branch. 2011-03-05 15:11:35 +01:00
python_exe.rc Issue #27756: Adds new icons for Python files and processes on Windows. Designs by Cherry Wang. 2016-09-05 14:05:17 -07:00
python_nt.rc 2016 will be another year of writing copyrighted code 2016-01-01 10:23:45 -06:00
python_uwp.cpp bpo-34977: Remove unused preprocessor definition (GH-11092) 2018-12-10 20:56:09 -08:00
python_ver_rc.h Closes #26624: Adds validation of ucrtbase[d].dll version with warning for old versions. 2016-04-12 20:11:25 -07:00
pythonw_exe.rc Issue #27756: Adds new icons for Python files and processes on Windows. Designs by Cherry Wang. 2016-09-05 14:05:17 -07:00
readme.txt Issue #25022: Merge with 3.4 2015-09-10 15:02:14 -05:00
sqlite3.rc Adds version info to all signed binaries on Windows. 2016-04-06 12:35:24 -07:00
store_info.txt bpo-34977: Add Windows App Store package (GH-11027) 2018-12-10 18:52:57 -08:00
testpy.py Cleanup regrtest "main()" function 2016-03-24 17:53:20 +01:00
validate_ucrtbase.py Issue #27705: Update message in validate_ucrtbase.py 2016-09-09 18:21:15 -07:00
WinMain.c Use UNICODE wWinMain, to make CRT initialize __wargv. 2008-05-09 17:06:49 +00:00
winreg.c bpo-35489: Use "const Py_UNICODE *" for the Py_UNICODE converter in AC. (GH-11150) 2018-12-14 11:19:51 +02:00
winsound.c Fix miscellaneous typos (#4275) 2017-11-05 15:37:50 +02:00

Welcome to the "PC" subdirectory of the Python distribution
***********************************************************

This "PC" subdirectory contains complete project files to make
several older PC ports of Python, as well as all the PC-specific
Python source files.  It should be located in the root of the
Python distribution, and there should be directories "Modules",
"Objects", "Python", etc. in the parent directory of this "PC"
subdirectory.  Be sure to read the documentation in the Python
distribution.

Python requires library files such as string.py to be available in
one or more library directories.  The search path of libraries is
set up when Python starts.  To see the current Python library search
path, start Python and enter "import sys" and "print sys.path".

All PC ports use this scheme to try to set up a module search path:

  1) The script location; the current directory without script.
  2) The PYTHONPATH variable, if set.
  3) For Win32 platforms (NT/95), paths specified in the Registry.
  4) Default directories lib, lib/win, lib/test, lib/tkinter;
     these are searched relative to the environment variable
     PYTHONHOME, if set, or relative to the executable and its
     ancestors, if a landmark file (Lib/string.py) is found ,
     or the current directory (not useful).
  5) The directory containing the executable.

The best installation strategy is to put the Python executable (and
DLL, for Win32 platforms) in some convenient directory such as
C:/python, and copy all library files and subdirectories (using XCOPY)
to C:/python/lib.  Then you don't need to set PYTHONPATH.  Otherwise,
set the environment variable PYTHONPATH to your Python search path.
For example,
   set PYTHONPATH=.;d:\python\lib;d:\python\lib\win;d:\python\lib\dos-8x3

There are several add-in modules to build Python programs which use
the native Windows operating environment.  The ports here just make
"QuickWin" and DOS Python versions which support a character-mode
(console) environment.  Look in www.python.org for Tkinter, PythonWin,
WPY and wxPython.

To make a Python port, start the Integrated Development Environment
(IDE) of your compiler, and read in the native "project file"
(or makefile) provided.  This will enable you to change any source
files or build settings so you can make custom builds.

pyconfig.h    An important configuration file specific to PC's.

config.c    The list of C modules to include in the Python PC
            version.  Manually edit this file to add or
            remove Python modules.

testpy.py   A Python test program.  Run this to test your
            Python port.  It should produce copious output,
	    ending in a report on how many tests were OK, how many
	    failed, and how many were skipped.  Don't worry about
	    skipped tests (these test unavailable optional features).


Additional files and subdirectories for 32-bit Windows
======================================================

python_nt.rc   Resource compiler input for python15.dll.

dl_nt.c
               Additional sources used for 32-bit Windows features.

getpathp.c     Default sys.path calculations (for all PC platforms).

dllbase_nt.txt A (manually maintained) list of base addresses for
               various DLLs, to avoid run-time relocation.


Note for Windows 3.x and DOS users
==================================

Neither Windows 3.x nor DOS is supported any more.  The last Python
version that supported these was Python 1.5.2; the support files were
present in Python 2.0 but weren't updated, and it is not our intention
to support these platforms for Python 2.x.