Description

dreamflow

opened on Dec 9, 2023

Issue body actions

Bug report

Bug description:

import ast
py_test_source = '''
def test() :
    """docstring"""
    assert True
    ...
'''
ast_obj = compile( # https://docs.python.org/library/functions.html#compile
    source = py_test_source ,
    filename = "" ,
    mode = "exec" ,
    flags = ast.PyCF_ONLY_AST ,
    dont_inherit = 1 ,
    optimize = 2 ,
) 
print( ast.unparse( ast_obj ) )

as i understand the compile() documentation ,
the above example should remove the docstring ,
and the assert line , but it doesn't .

setting the env var PYTHONOPTIMIZE=2 and then
running python with the cmdLine option -OO
this time with
a) compile( ... , dont_inherit=False , ... ) without optimize
b) compile( ... , dont_inherit=0 , ... ) without optimize
c) compile( ... ) without : dont_inherit , optimize
didn't chage the outcome :
compile() never removes docstrings/asserts .

looks like compile() ignores its arg optimize=2
and -OO and PYTHONOPTIMIZE=2 .

CPython versions tested on:

3.11.5

Operating systems tested on:

Windows 10 (22H2) 64bit

Activity

1. dreamflow

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Dec 9, 2023
2. dreamflow

   changed the title [-]compile( optimize=2 ) doesn't del docstrings , ignores -OO & PYTHONOPTIMIZE=2[/-] [+]compile( optimize=2 ) doesn't del asserts/docstrings , ignores -OO & PYTHONOPTIMIZE=2[/+] on Dec 9, 2023
3. dreamflow

   changed the title [-]compile( optimize=2 ) doesn't del asserts/docstrings , ignores -OO & PYTHONOPTIMIZE=2[/-] [+]compile( optimize=2 ) doesn't del docstrings/asserts , ignores -OO & PYTHONOPTIMIZE=2[/+] on Dec 9, 2023
4. terryjreedy

   added

   pendingThe issue will be closed if no feedback is providedThe issue will be closed if no feedback is provided

   and removed

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Dec 10, 2023
5. terryjreedy commented on Dec 10, 2023

   

   terryjreedy

   on Dec 10, 2023

   Member

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   The doc says "The argument optimize specifies the optimization level of the compiler;". With the PyCF_ONLY_AST, you are only running the parser, not the compiler itself. If the parser stripped docstrings and assert statements, then unparse would not work right. Also, def f(): "docstring"` would not compile as the docstring is, here, the required non-empty suite.

   If you compile to a code object and exec the code object, the resulting test function object will not have a docstring or assert.

   test = '''\
   def test() :
       """docstring"""
       assert False
   '''
   
   exec(compile( 
       source = test,
       filename = "" ,
       mode = "exec" ,
   #    flags = ast.PyCF_ONLY_AST ,
       dont_inherit = 1 ,
       optimize = 2 ,
   ))
   
   print(test.__doc__, test())  # prints `None None`

   Perhaps the doc could be clearer to Python learners, but I am not sure how.
6. dreamflow commented on Dec 10, 2023

   

   dreamflow

   on Dec 10, 2023

   ContributorAuthor

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   thank you terryjreedy for the detailed explanation 🙂
7. hugovk

   changed the title [-]compile( optimize=2 ) doesn't del docstrings/asserts , ignores -OO & PYTHONOPTIMIZE=2[/-] [+]compile(optimize=2 ) doesn't del docstrings/asserts , ignores -OO & PYTHONOPTIMIZE=2[/+] on Dec 10, 2023
8. hugovk

   changed the title [-]compile(optimize=2 ) doesn't del docstrings/asserts , ignores -OO & PYTHONOPTIMIZE=2[/-] [+]compile(optimize=2) doesn't del docstrings/asserts, ignores -OO & PYTHONOPTIMIZE=2[/+] on Dec 10, 2023
9. carljm commented on Dec 17, 2023

   

   carljm

   on Dec 17, 2023

   Member

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   This is a duplicate of #108113. In #108154 @iritkatriel added PyCF_OPTIMIZED_AST to solve this (but for Python 3.13+ only.)

   Reacted by dreamflow
10. carljm

    closed this as completedon Dec 17, 2023
11. carljm

    closed this as not plannedon Dec 17, 2023

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