347 def stringtoint(bitstring):  argument
349     size = len(bitstring)
351         acc = acc + (ord(bitstring[i]) * (2**(8*(size - 1 - i))))
361 def expand(bitstring, bitlen, direction):  argument
363     if len(bitstring) >= bytelen:
364         return bitstring
367             return ((bytelen-len(bitstring))*"\x00") + bitstring
369             return bitstring + ((bytelen-len(bitstring))*"\x00")
373 def truncate(bitstring, bitlen, keep):  argument
378     strbitlen = 8*len(bitstring)
382 …      return expand(inttostring(stringtoint(bitstring) >> int(strbitlen - bitlen)), bitlen, "LEFT")
385             return expand(inttostring(stringtoint(bitstring) & mask), bitlen, "LEFT")
390         return bitstring