Pyright: Incorrect "'symbol' is unknown import symbol" in 1.0.83

[hugodutka]

Describe the bug
For constructions like from module import symbol Pyright 1.0.83 for VS Code reports that 'symbol' is unknown import symbol if the module was installed with pip. The same behaviour does not exist in 1.0.82.

To Reproduce
I am using a virtual environment created with pyenv. Install any package with pip. Create a new file or open an existing one and import any symbol from the package.

Expected behavior
Pyright should not show the error.

Screenshots or Code
Minimal example:

from flask import Flask

VS Code extension or command-line
VS Code extension 1.0.83.

Additional context
I have not checked if the problem exists in venvs created with anything else than pyenv. I encountered the problem on macOS.

[sotanodroid]

Confirm issue also shows up with environments created with pipenv.

[erictraut]

Thanks for the bug report. I'm able to repro the problem, and I'll work on a fix.

[erictraut]

OK, I found the cause of this regression. A fix will be in the next version. Sorry for the inconvenience.

[erictraut]

This is now fixed in 1.0.84, which I just published.

[mvolkmann]

@erictraut I am still seeing this issue. Perhaps my configuration file is wrong. Here is a very basic example.

math.py

PI = 3.1415928

def add(n1, n2):
    return n1 + n2

typings/math.pyi

PI: float

def add(n1: float, n2: float) -> float: ...

demo.py

from math import PI, add

print(add('2', PI)) # expecting type error for first argument

pyrightconfig.json

{
  "strict": ["."]
}

When I enter pyright I get:

Found 4 source files
/Users/mark/Documents/programming/languages/Python/types/demo.py
  1:18 - error: "PI" is unknown import symbol (reportGeneralTypeIssues)
  1:22 - error: "add" is unknown import symbol (reportGeneralTypeIssues)
  3:7 - error: Argument type is unknown
    Argument corresponds to parameter "values" in function "print" (reportUnknownArgumentType)
/Users/mark/Documents/programming/languages/Python/types/math.py
  3:9 - error: Type of parameter "n1" is unknown (reportUnknownParameterType)
  3:13 - error: Type of parameter "n2" is unknown (reportUnknownParameterType)
  4:12 - error: Return type is unknown (reportUnknownVariableType)
  3:5 - error: Return type is unknown (reportUnknownParameterType)

[erictraut]

math is the name of a stdlib module, and it's resolving to the math.pyi that ships with pyright.

As a workaround, choose a name other than math for your module.

[mvolkmann]

@erictraut Ah, that helped! It now catches the type error I expected it to catch. But also thinks the parameter and return types in math_util.py are unknown. Shouldn't it think they are known because I define them in math_util.pyi?

Found 4 source files
/Users/mark/Documents/programming/languages/Python/types/demo.py
  3:11 - error: Argument of type "Literal['2']" cannot be assigned to parameter "n1" of type "float" in function "add"
    "Literal['2']" is incompatible with "float" (reportGeneralTypeIssues)
/Users/mark/Documents/programming/languages/Python/types/math_util.py
  3:9 - error: Type of parameter "n1" is unknown (reportUnknownParameterType)
  3:13 - error: Type of parameter "n2" is unknown (reportUnknownParameterType)
  4:12 - error: Return type is unknown (reportUnknownVariableType)
  3:5 - error: Return type is unknown (reportUnknownParameterType)
5 errors, 0 warnings, 0 infos

[erictraut]

Pyright will use the types from math_util.pyi when analyzing demo.py, but you are also asking pyright to type check the file math_util.py. By default, pyright will analyze all ".py" files in the workspace. If you want to include or exclude specific files or directories, you need to configure it to do so.

If math_util.py is your own module, you could just provide types inline within the code rather than mess around with the added complexity of a type stub file.

[mvolkmann]

@erictraut Thanks for explaining that. IIUC this differs from how mypy works. I think mypy first checks for types in .pyi files and those override any types in corresponding .py files. It doesn't report errors for omitting types in .py files if the corresponding .pyi file defines them.

The only reason I put the types in a .pyi file is that I just wanted to learn how to use those files.

[erictraut]

If you ask mypy to analyze math_util.py, it will do so even if a math_util.pyi happens to be present. If you analyze a different file (like demo.py) that imports math_util, mypy will use the type information from math_util.pyi. Pyright does the same thing.

AFAIK, mypy doesn't offer a "strict" mode that emits errors for unknown types, so in that respect pyright differs from mypy.

[mvolkmann]

Ah, I didn't catch the distinction between running "pyright" and running "pyright demo.py". Thanks!