How do I check if a number is a 32-bit integer using Python?

Question

In my program I'm looking at a string and I want to know if it represents a 32-bit integer.

Currently I first check if it is a digit at all using isdigit(), then I check if it exceeds the value of 2^32 (assuming I don't care about unsigned values).

What's the best way to check that my input string contains a valid 32-bit integer?

Answer 1

We can use left shift operator to apply the check.

def check_32_bit(n):
    return n<1<<31

Answer 2

For unsigned values, this will work:

>>> def is32(n):
...     try:
...         bitstring=bin(n)
...     except (TypeError, ValueError):
...         return False
...         
...     if len(bin(n)[2:]) <=32:
...         return True
...     else:
...         return False    
... 
>>> is32(2**32)
False
>>> is32(2**32-1)
True
>>> is32('abc')
False