decimal_to_binary.py

decimal_to_binary.py

  1 def decimal_to_binary(num, rems):
  2     if num == 0:
  3         return rems[::-1]
  4     else:
  5         rem = num % 2
  6         rems.append(rem)
  7         return decimal_to_binary(num // 2, rems)
  8
  9 assert decimal_to_binary(193, []) == [1,1,0,0,0,0,0,1]
 10
 11
 12 def binary_to_decimal(binary, place_value, decimal_value):
 13     '''
 14 assuming the binary is numbers are given in list like [1,1,0,0,0,0,0,1]
 15 return back 193
 16 counting from right to left is more convinent, as the base value goes on increasing by 2 every time
 17     '''
 18     if binary  == []:
 19         return decimal_value
 20     else:
 21         last_bit = binary.pop()
 22         return binary_to_decimal(binary, place_value *2, decimal_value + place_value * last_bit)
 23
 24 assert binary_to_decimal([1,1,0,0,0,0,0,1], 1, 0) == 193