用pytest --fixtures [testpath] 显示no docstring available

The "no docstring available" message that you are seeing when running "pytest --fixtures [testpath]" indicates that there is no docstring (i.e., documentation string) available for the fixture that you are trying to display.

A docstring is a string literal that appears as the first statement in a module, function, class, or method definition. It is used to provide documentation for the code and is accessible via the "__doc__" attribute of the object.

To add a docstring to a fixture, you can simply add a string as the first line of the fixture function definition. For example:

import pytest

@pytest.fixture
def my_fixture():
    """
    This is the docstring for my_fixture.
    """
    return 42

When you run "pytest --fixtures [testpath]" again, you should see the docstring displayed for the "my_fixture" fixture.