Issue 28975: os.walk generator giving inconsistent results (original) (raw)

Created on 2016-12-14 22:08 by Colin David Chen, last changed 2022-04-11 14:58 by admin. This issue is now closed.

Messages (4)
msg283221 - (view)	Author: Colin David Chen (Colin David Chen)	Date: 2016-12-14 22:08
os.walk in 3.6rc1 (Windows) appears to generate different output depending on its invocation. In the first invocation, I use the generator to yield one result at a time: source = "C:\\cdchen_data\\downloads\\python-xlib-0.18\\" texasranger = os.walk(Path(source)) roottree = [next(texasranger)] roottree[0][0] Output: 'C:\\cdchen_data\\downloads\\python-xlib-0.18' The same result occurs when using the generator in a for loop. In the second invocation, I generate the complete list first: sourcetree = [x for x in os.walk(source)] sourcetree[0][0] Output: 'C:\\cdchen_data\\downloads\\python-xlib-0.18\\' The particular behavior causing me trouble is the omission in the first result of the final '\\'. I checked in 2.7.6 and os.walk is consistent and I believe more correct in that it will yield equivalent results and includes the '\\'. Not sure if earlier Python 3 implementations have this problem, I couldn't get 3.5 to run this function without failing.
msg283222 - (view)	Author: Eric V. Smith (eric.smith) *	Date: 2016-12-14 22:15
Isn't the difference that you use os.walk(Path(source)) in the first example, and os.walk(source) in the second one?
msg283223 - (view)	Author: Eric V. Smith (eric.smith) *	Date: 2016-12-14 22:19
Assuming Path is pathlib.Path, this is equivalent to the difference between: >>> list(os.walk('/tmp')) [('/tmp', <other-stuff ...> and: >>> list(os.walk('/tmp/')) [('/tmp/', <other-stuff ...> Because: >>> pathlib.Path('/tmp') PosixPath('/tmp') >>> pathlib.Path('/tmp/') PosixPath('/tmp')
msg283224 - (view)	Author: Colin David Chen (Colin David Chen)	Date: 2016-12-14 22:32
Ah, you're correct. The behavior is consistent if you use strings in both invocations. The Path conversion strips the final '\\'. Doc examples do use the names of directories rather than a Path object. I will close the issue. Thanks for the quick response!