zip as iterator and bad/good practices

[Laura Creighton]

The real problem is removing things from lists when you are iterating
over them, not adding things to the end of lists.

Python 2.7.9 (default, Mar  1 2015, 12:57:24)
[GCC 4.9.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> mylist = [1,2,3]
>>> for i in mylist:
...     print i
...     mylist.remove(i)
...
1
3
>>> mylist
[2]

Most people expect 1 2 and 3 to get printed, and mylist to be empty at
the end of this loop.

Laura