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symtable: repr() of a Symbol raises TypeError under -X lazy_imports=all

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Since Oct 29, 2026.

Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
72/100
Issue type
Bug
Clarity
Clearly specified
Activity status
Active
Tech stack
python
Domain
testing

Research direction

Read Lib/symtable.py, especially where _flags and _scopes_value_to_name are built from globals(), and compare those names with the constants in _symtable. Start by running the reported repr() example with -X lazy_imports=all; then run test_symtable with and without lazy imports. Done means symbols show their expected flags and scope names in both modes, and the test no longer needs exclusion from Lib/test/lazy_imports_all_exclude.txt.

Written by the indexing model from the issue text.

Description

stdlib topic-lazy-imports type-bug

Bug report

Bug description:

With -X lazy_imports=all, repr() of a symtable.Symbol raises TypeError:

import symtable
top = symtable.symtable('x = 1', '<string>', 'exec')
print(top.get_symbols())

$ ./python -X lazy_imports=all repro.py
Traceback (most recent call last):
  File "repro.py", line 3, in <module>
    print(top.get_symbols())
    ~~~~~^^^^^^^^^^^^^^^^^^^
  File "Lib/symtable.py", line 264, in __repr__
    flags_str = '|'.join(self._flags_str())
  File "Lib/symtable.py", line 272, in _flags_str
    if self.__flags & flagvalue == flagvalue:
       ~~~~~~~~~~~~~^~~~~~~~~~~
TypeError: unsupported operand type(s) for &: 'int' and 'lazy_import'

Without the option it prints [<symbol 'x': LOCAL, DEF_LOCAL>].

Lib/symtable.py builds its _flags and _scopes_value_to_name tables from globals(): https://github.com/python/cpython/blob/c79146a9eb05dea735a6a22dc004379cdec3ed0e/Lib/symtable.py#L388-L391

With lazy_imports=all, the from _symtable import ... at the top of the module is lazy, so globals() holds lazy_import objects instead of the integer constants. _flags breaks repr() as above, and once that is fixed, _scopes_value_to_name still makes the scope print as 1 instead of LOCAL.

This is the test_symtable failure mentioned in gh-149640, and why test_symtable is in Lib/test/lazy_imports_all_exclude.txt. The 3.15 branch has the same code.

Possible fix: take the values from the _symtable module (for example getattr(_symtable, name)) instead of from globals(). With that, test_symtable passes with and without -X lazy_imports=all and can come off the exclusion list. I can open a PR if this sounds right.

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs
  • gh-160866
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Python
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