Terry J. Reedy <tjre...@udel.edu> added the comment:
Sandro, import is a somewhat dark corner of Python that newcomers and even
experienced people ofter trip over. So getting the text both correct and clear
is worth some thought.
I just noticed that the text is only true for Python-coded modules and not for
built-in modules. I discovered this by setting sys.path to {} and importing
itertools. It works. It appears that Python first searches for builtins -- I
created itertools.py and it did not mask the builtin. If there were a
Lib/itertools.py which imported _itertools, it would have been masked. So it
appears that the text should begin
"When a module named :mod:`spam` is imported, the interpreter first searches
for a built-in module with that name. If not found, it then searches for a file
..."
I suggest changing
"This allows Python programs to modify or replace the module search path."
to
"After initialization, Python programs can modify sys.path."
and changing the followup
" Note that because the directory containing the script being run is on the
search path, it is important that the script not have the same name as a
standard module, or Python will attempt to load the script as a module when
that module is imported. This will generally be an error."
to something more like
"Because the directory containing the script being run is placed at the
beginning of the search path, ahead of the standard library path, the script
and other scripts in that directory should not have the same name as a standard
library module unless one really intends for the script to be loaded in place
of the standard library module."
or perhaps
"The directory containing the script being run is placed at the beginning of
the search path, ahead of the standard library path. This means that scripts in
that directory will be loaded instead of modules of the same name in the
library directory. This is an error unless the replacement is intended."
I think the change to warn about all possibly conflicting scripts in the
directory is needed because a common problem people have is more like
import random
a = random.choice('abc')
raising AttributeError ("O python-list, why???") because there is a forgotten
random.py in the same directory.
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<http://bugs.python.org/issue11948>
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