old_contents: def a(x,y=None):
      """Takes two ints, or a list of ints"""
      if y:
          return x.__add__(y)
      else:
          result = 0
          for item in x:
              result = result.__add__(item)
          return result
  
  def b(x,y=None):
      """Takes two ints, or a list of ints"""
      if y:
          return x.__sub__(y)
      else:
          result = 0
          for item in x:
              result = result.__sub__(item)
          return result
  
  def c(x,y=None):
      """Takes two ints, or a list of ints"""
      if y:
          return x.__mul__(y)
      else:
          result = 1
          for item in x:
              result = result.__mul__(item)
          return result
  
  def d(x,y=None):
      """Takes two ints, or a list of ints"""
      if y:
          return x.__floordiv__(y)
      else:
          result = 1
          for item in x:
              result = result.__floordiv__(item)
          return result
  
new_contents: from __future__ import division
  
  def a(x,y=None):
      """Takes two ints, or a list of ints"""
      if y:
          return x.__add__(y)
      else:
          result = 0
          for item in x:
              result = result.__add__(item)
          return result
  
  def b(x,y=None):
      """Takes two ints, or a list of ints"""
      if y:
          return x.__sub__(y)
      else:
          result = 0
          for item in x:
              result = result.__sub__(item)
          return result
  
  def c(x,y=None):
      """Takes two ints, or a list of ints"""
      if y:
          return x.__mul__(y)
      else:
          result = 1
          for item in x:
              result = result.__mul__(item)
          return result
  
  def d(x,y=None):
      """Takes two ints, or a list of ints"""
      if y:
          return x.__floordiv__(y)
      else:
          result = 1
          for item in x:
              result = result.__truediv__(item)
          return result
  
subject: Use truediv, not floordiv