new_contents: class Solution(object):
      def addBinary(self, a, b):
          """
          :type a: str
          :type b: str
          :rtype: str
          """
          res = ''
          tc = 0
          for i in range(max(len(a), len(b))):
              ta = int(a[-i - 1]) if i < len(a) else 0
              tb = int(b[-i - 1]) if i < len(b) else 0
              res = str((ta + tb + tc) % 2) + res
              tc = (ta + tb + tc) / 2
          if tc:
              res = '1' + res
          return res
  
subject: Create AddBinary_003.py