77
votes

In Python, is there a way to get the largest integer one can use? Is there some pre-defined constant like INT_MAX?

1
It is 2^31 - 1 in Python 32 and 2^63 - 1 Python 64 bit runtime system.Vlad Bezden

1 Answers

130
votes

Python has arbitrary precision integers so there is no true fixed maximum. You're only limited by available memory.

In Python 2, there are two types, int and long. ints use a C type, while longs are arbitrary precision. You can use sys.maxint to find the maximum int. But ints are automatically promoted to long, so you usually don't need to worry about it:

sys.maxint + 1

works fine and returns a long.

sys.maxint does not even exist in Python 3, since int and long were unified into a single arbitrary precision int type.