d = {'a': 1, 'b': 2, 'c': 3}
for key in d:
    print key
for key in d.itervalues():
    print key
for k,v in d.iteritems():
    print k,v
for ch in 'ABC':
    print ch
from collections import Iterable
print isinstance('abc', Iterable)
print isinstance([1,2,3], Iterable)
print isinstance(123, Iterable)
for i, value in enumerate(['A', 'B', 'C']):
    print i,value
for x, y in [(1, 1), (2, 4), (3, 9)]:
    print x, y