In Python 3, this question doesn’t apply. The plain
int type is unbounded.
However, you might actually be looking for information about the current interpreter’s word size, which will be the same as the machine’s word size in most cases. That information is still available in Python 3 as
sys.maxsize, which is the maximum value representable by a signed word. Equivalently, it’s the size of the largest possible list or in-memory sequence.
Generally, the maximum value representable by an unsigned word will be
sys.maxsize * 2 + 1, and the number of bits in a word will be
math.log2(sys.maxsize * 2 + 2). See this answer for more information.
In Python 2, the maximum value for plain
int values is available as
>>> sys.maxint 9223372036854775807
You can calculate the minimum value with
-sys.maxint - 1 as shown here.
Python seamlessly switches from plain to long integers once you exceed this value. So most of the time, you won’t need to know it.