Padded Binary

# Debugging a problem in a Verilog simulation. Needed a convenient way to print values as binary while padded to the bus width.
class PaddedBinary(object):
    def __init__(self,numbits):
        self.numbits = numbits

    def __call__(self,num):
        s = bin(num)[2:]  # trim off the leading '0b'
        s = ('0'*(self.numbits-len(s))) + s
        return s

padbin68 = PaddedBinary(68)
print(padbin68(0x4242))

padbin48 = PaddedBinary(48)
print(padbin48(0x4242))

output:
00000000000000000000000000000000000000000000000000000100001001000010
000000000000000000000000000000000100001001000010