def asBinary(self):
        """Get |ASN.1| value as a text string of bits.
        """
        binString = binary.bin(self._value)[2:]
        return '0' * (len(self._value) - len(binString)) + binString
Get |ASN.1| value as a text string of bits.
        
stackoverflow/venv/lib/python3.6/site-packages/pyasn1/type/univ.py