enumerate

for key, value in enumerate(["p", "y", "t", "h", "o", "n"]):
    print key, value

"""
0 p
1 y
2 t
3 h
4 o
5 n
"""

presidents = ["Washington", "Adams", "Jefferson", "Madison", "Monroe", "Adams", "Jackson"]
for num, name in enumerate(presidents, start=1):
    print("President {}: {}".format(num, name))