convert version numbers into one number

ver2num.py

#!/usr/bin/env python
"""
Convert version number of only digits into one number, ready for comparing.
"""

v1=(1,20,0,10)
v2=(1,20,1,0)

# length in bits of each version number.
# for example '8' allows to use version number with elements of a max 256: "256.256.256.256"
VER_ELEM_BITS=8

def ver_to_num(a,b,c,d):
    res = (a<<(VER_ELEM_BITS*3)) + (b<<(VER_ELEM_BITS*2)) + (c<<VER_ELEM_BITS) + d
    return res

v1=ver_to_num(*v1)
v2=ver_to_num(*v2)

if v2 > v1:
    print('ok',v2)
elif v2 == v1:
    print('equal',v2)
else:
    print('v2 should be greater',v2)