from pygments.lexers import DiffLexer unknown

[eddy-geek]

Environment data

• Language Server version: XXX
• OS and version: XXX
• Python version (& distribution if applicable, e.g. Anaconda): XXX

Expected behaviour

Typechecking pygments code (pip install pygments) should work:

from pygments.lexers import DiffLexer
from pygments.formatters import HtmlFormatter

Actual behaviour

prints DiffLexer is unknow import symbol

Code Snippet / Additional information

See the pygments/lexers/init.py:

from pygments.lexers._mapping import LEXERS
__all__ = ['get_lexer_by_name', 'get_lexer_for_filename', 'find_lexer_class',
           'guess_lexer', 'load_lexer_from_file'] + list(LEXERS) + list(COMPAT)

#...

class _automodule(types.ModuleType):
    """Automatically import lexers."""
    #...
oldmod = sys.modules[__name__]
newmod = _automodule(__name__)
newmod.__dict__.update(oldmod.__dict__)
sys.modules[__name__] = newmod
...

I understand you might not want to support the sys.modules[__name__] = newmod hack, but it seems to me that just parsing the __ALL__ line (and using it as a heuristic for what can be imported, I know it can be different) might go a long way here.

[erictraut]

This library is using a dynamic expression to define __ALL__ — one that static type checkers like pylance do not understand. There are a limited number of forms of __ALL__ that static type checkers honor. The list can be found here. The maintainers of pygments will need to stick to this list if they want their library to work with static type checkers.

In the meantime, you can work around the problem by importing the module one level deeper:
from pygments.lexers.diff import DiffLexer

[judej]

Closing this in this repo since the work is not here in Pylance.