I am not able to reproduce your issue. Is mypy also complaining ? what version of python/schema are you using ?

Mypy does not complain in that minimal example (even when in strict mode), but does complain when moving And out of the schema:

And(str, Use(str.lower), lambda s: s in ('alice', 'bob'))
# Mypy reports: Argument 2 to "And" has incompatible type "Use"; expected "Callable[..., Any]"
# VS Code (pyright) reports: The type 'Use' is incompatible with the types 'Schema' and '(...) -> Any'
# PyCharm reports something similar to VS Code

{'party': And(str, Use(str.lower), lambda s: s in ('alice', 'bob'))}
# Mypy still complains

Schema({'party': And(str, Use(str.lower), lambda s: s in ('alice', 'bob'))})
# Mypy does not report anything

I haven't used Mypy before, so I'm not sure if it is a bug.

I'm using schema 0.7.7 on Python 3.12. Mypy's version 1.11.1.

ok, I now have the same issue. No solution yet but as a dirty workaround you can replace

Use(str.lower)

with

eval("Use(str.lower)")

ok, I now have the same issue. No solution yet but as a dirty workaround you can replace

Use(str.lower)

with

eval("Use(str.lower)")

That's really ugly. Why not just ignore the error?

# type: ignore

@mutricyl By the way, not to criticize, but I noticed your markdown code snippet looks like this (copy and pasted from your comment):

> ```python
> print("Hello World!")
> ```

Those greater than symbols are unnecessary. Just typing ``` is sufficient:

```python
print("Hello World!")
```

Hope this helps!

ok, I now have the same issue. No solution yet but as a dirty workaround you can replace

Use(str.lower)

with

eval("Use(str.lower)")

Understood, thank you. Now I've put all schemas in a single file, so I can just disable type checking for that file. I'm comfortable with this.

I agree that the eval trick is ugly. You can narrow the type ignore to the specific issue : # type: ignore[call-arg] likewise if pyright complains: # pyright: ignore[<whateverPyrightIssueName>]

Apparently mypy does not consider Use as being a callable. I have added a __call__ function to Use class and it looks to solve the issue.

class Use:
 
(...)

    def __call__(self, *args: Any, **kwds: Any) -> Any:
        pass

However I still have an issue mixing And and Or.