why does math.pow yields OverflowError (while python itself can calculate that large number)

[Tzury Bar Yochay]

> Because math.pow returns a float; 100 ** 155 won't fit in a float.

Sure that is the reason.
May I rephrase, my question:
Why not returning another type as long as we can calculate it?
After all, math module is likely to be used on large numbers as well.