Dan39.py

def bit_iter(bits, n):
    "Iterate over the bits of an integer, padding it to `n` digits."
    return ((bits >> i) & 1 for i in xrange(n - 1, -1, -1))

def unsigned_bin(x, n=32):
    "Print the unsigned binary representation of an integer."
    return "".join(repr(y) for y in bit_iter(x, n))
    

print unsigned_bin(0b101, 8) # '00000101'
print usngined_bin(~0b101, 8) # '11111010'