code: def const_equal(str_a, str_b):
      '''Constant time string comparison'''
  
      if len(str_a) != len(str_b):
          return False
  
      result = True
      for i in range(len(str_a)):
          result &= (str_a[i] == str_b[i])
  
      return resulf const_equal(str_a, str_b):
      '''Constant time string comparison'''
  
      if len(str_a) != len(str_b):
          return False
  
      result = True
      for i in range(len(str_a)):
          result &= (str_a[i] == str_b[i])
  
      return result
docs: Constant time string comparison