Convert IP to int and back from int to IP

ipconvert.py

"""
Convert IPv4 to unsigned int
"""
def ip2uint(ip):
    dot1 = ip.index('.')
    dot2 = ip.index('.', dot1 + 1)
    dot3 = ip.index('.', dot2 + 1)
    i1 = int(ip[0: dot1])
    i2 = int(ip[dot1 + 1: dot2])
    i3 = int(ip[dot2 + 1: dot3])
    i4 = int(ip[dot3 + 1:])
    uintip = (i1 << 24) + (i2 << 16) + (i3 << 8) + i4
    return uintip

"""
Convert IPv4 stored in unsigned int back to string
"""
def uint2ip(uintip):
    x1 = uintip >> 24
    x2 = (uintip - (x1 << 24)) >> 16
    x3 = (uintip - (x1 << 24) - (x2 << 16)) >> 8
    x4 = (uintip - (x1 << 24) - (x2 << 16) - (x3 << 8))
    return '{0}.{1}.{2}.{3}'.format(x1, x2, x3, x4)