Terry Reedy wrote: > Alexander Belopolsky wrote: >> Terry Reedy wrote: >>> I had exactly the same idea, but did not post because it violates the >>> general rule that mutators return None. >> >> Is there such a rule? What about set/dict pop? > > The rule perhaps should be restated as 'Collection mutators return None > or possible an item but not the collection.'
And to clarify the rationale for that guideline: it is to make it clear that the mutator is changing the container in place and *not* creating a new container object. myset.pop() # No new container, returns popped object mylist.sort() # No new container, returns None sorted(mylist) # New container, so return it mystr.lower() # Creates new string, so return it Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia --------------------------------------------------------------- _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
