_nibbles = {"0":"0000", "1":"0001", "2":"0010", "3":"0011", "4":"0100", "5":"0101", "6":"0110", "7":"0111", "8":"1000", "9":"1001", "A":"1010", "B":"1011", "C":"1100", "D":"1101", "E":"1110", "F":"1111", "-":"-"} def toBase2(number): """toBase2(number): given an int/long, converts it to a string containing the number in base 2.""" # From a suggestion by Dennis Lee Bieber. if number == 0: return "0" result = [_nibbles[nibble] for nibble in "%X"%number] result[number<0] = result[number<0].lstrip("0") return "".join(result) # Small test: for i in xrange(-20, 21): print toBase2(i) for i in xrange(-1000, 1000): if i != int(toBase2(i),2): print "Different"