`configparser.RawConfigParser` stub does not account for non-string options

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Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
68/100
Issue type
Bug
Clarity
Clearly specified
Activity status
Stale
Tech stack
python
Domain
tooling

Research direction

Start with stdlib/configparser.pyi around line 133 and compare the RawConfigParser.set signature with the behavior shown in the issue. Run the provided script through mypy to reproduce the false positives, then verify that boolean, integer, and bytes values are accepted without errors while the existing get behavior remains covered.

Written by the indexing model from the issue text.

Description

stubs: false positive

The stub for configparser.RawConfigParser.set has its value argument typed as str | None (source) when it can accept lots of other types and is leading to a false positive in mypy for me.

Consider this valid script:

from configparser import RawConfigParser

cfg = RawConfigParser()
cfg.add_section("default")

cfg.set("default", "some_option1", True)
r1 = cfg.get("default", "some_option1")
print(r1, type(r1))


cfg.set("default", "some_option2", 1)
r2 = cfg.get("default", "some_option2")
print(r2, type(r2))

cfg.set("default", "some_option3", b"bytes")
r3 = cfg.get("default", "some_option3")
print(r3, type(r3))

It prints:

True <class 'bool'>
1 <class 'int'>
b'bytes' <class 'bytes'>

However, mypy flags this code for the reason described above:

test.py:6: error: Argument 3 to "set" of "RawConfigParser" has incompatible type "bool"; expected "Optional[str]"
test.py:11: error: Argument 3 to "set" of "RawConfigParser" has incompatible type "int"; expected "Optional[str]"
test.py:15: error: Argument 3 to "set" of "RawConfigParser" has incompatible type "bytes"; expected "Optional[str]"
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