iter(sequence) or iter(callable, sentinel)
Returns an iterator object. If a single sequence
argument is given, it must be a sequence object which supports the
iteration protocol (the
__iter__ method) or the sequence protocol (the __getitem__ method with
integer arguments starting at 0). If it does not
support either of those protocols, TypeError is raised.
If two arguments are given, the first argument must be a callable object. The iterator created in this case will call the callable with no arguments for each call to its next method; if the value returned is equal to sentinel, StopIteration will be raised, otherwise the value will be returned.
(New in version 2.2.)