Bug report

Bug description:

When a file: URL is given to urllib.request.urlopen(), it returns an addinfourl object. This object's url attribute (and its deprecated geturl() method) usually return incorrect results. For example:

>>> from urllib.request import urlopen
>>> urlopen('file:Doc/requirements.txt').url
'file://Doc/requirements.txt'   # expected: 'file:Doc/requirements.txt'
>>> urlopen('file:C:/requirements.txt').url
'file://C:/requirements.txt'  # expected: 'file:C:/requirements.txt' or 'file:///C:/requirements.txt'

The code always prepends file://, but this might be too many slashes or too few depending on the path's drive and root.

CPython versions tested on:

CPython main branch

Operating systems tested on:

No response

Linked PRs

• GH-127090: Fix urllib.response.addinfourl.url value for opened file: URIs #127091