Lib/inspect.py: Avoid wild replacement in formatannotation

[iyume]

Bug report

Source:

cpython/Lib/inspect.py

Lines 1449 to 1458 in 91afe66

	def formatannotation(annotation, base_module=None):
	if getattr(annotation, '__module__', None) == 'typing':
	return repr(annotation).replace('typing.', '')
	if isinstance(annotation, types.GenericAlias):
	return str(annotation)
	if isinstance(annotation, type):
	if annotation.__module__ in ('builtins', base_module):
	return annotation.__qualname__
	return annotation.__module__+'.'+annotation.__qualname__
	return repr(annotation)

An error replacement happens in:

repr(annotation).replace('typing.', '')

Suppose that I define a class or Protocol under foo/typing.py:

class A:
    pass

Then Union[int, A] will turn to Union[int, foo.A], but expected result is Union[int, foo.typing.A]

Any module with suffix like xxtyping will be replaced, such as nptyping.

Solution

Replace the line to:

        def repl(match):
            text = match.group()
            if text.startswith('typing.'):
                    return text[len('typing.'):]
            return text
        return re.sub(r'[\w\.]+', repl, repr(annotation))