This is in reference to the thread on python-dev
starting 2004/07/07, subject "file() or open()?". Guido
stated there that one should use open() to open files:

"""Anyway, here's my future-proof distinction: use
open() as the factory function, and file for
type-testing."""

The docs, however, still convince the reader that
open() is retained for backwards compatibility and near
deprecation. This patch corrects the issue, mostly
using Guido's own new wording.