Chris Angelico <ros...@gmail.com> writes: > Other people have explained the problem with your code. I'll take this > example as a way of introducing you to one of Python's handy features > - it's an idea borrowed from functional languages, and is extremely > handy. It's called the "list comprehension", and can be looked up in > the docs under that name, > > def testFunc(startingList): > xOnlyList = [strng for strng in startingList if strng[0] == 'x'] > startingList = [strng for strng in startingList if strng[0] != 'x'] > print(xOnlyList) > print(startingList) > > It's a compact notation for building a list from another list. (Note > that I changed "str" to "strng" to avoid shadowing the built-in name > "str", as others suggested.)
Fully agree with you: list comprehension is, imo, the most useful program construct ever. Extremely useful. But not when it makes the program traverse twice the same list, where one traversal is enough. -- Alain. -- http://mail.python.org/mailman/listinfo/python-list
