On 21 August 2015 at 02:57, Alan Gauld <alan.ga...@btinternet.com> wrote: > On 20/08/15 09:51, Srihari Vijayaraghavan wrote: > >> In general I agree, but this is what the os.walk() document states: >> "... When topdown is True, the caller can modify the dirnames list >> in-place (perhaps using del or slice assignment)..." > > > That's true so far as the os.walk call goes. > That is, altering dirs does not have any nagative > impact on the subsequent iterations of os.walk. > So even if you delete items from dirs os.walk will > continue to iterate over those deleted directories > in subsequent calls to os.walk()
Thanks Alan. That's now practically learnt :-). > But altering dirs within the current iteration does affect > dirs within that iteration, just like any other collection. > So your for loop inside the os.walk loop is affected by the > deletions even if the outer os.walk loop is not. Yes, it was a bad idea to update dirs list while iterating over it. I was confused/mislead by the documentation, perhaps by misinterpreting it. Never mind, now it's quite clear that it's a no-no. Thanks your quick & perfect analysis. Srihari Vijayaraghavan _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
