python - 如何避免使用全局变量？

Question

我使用全局变量，但我读过它们不是一个好的做法或 pythonic。我经常使用的函数会给出许多我需要在主函数中使用的 yes/no 变量。例如，如何在不使用全局变量的情况下编写以下代码？

def secondary_function():
    global alfa_is_higher_than_12
    global beta_is_higher_than_12

    alfa = 12
    beta = 5

    if alfa > 10:
        alfa_is_higher_than_12 = "yes"
    else:
        alfa_is_higher_than_12 = "no"

    if beta > 10:
        beta_is_higher_than_12 = "yes"
    else:
        beta_is_higher_than_12 = "no"

def main_function():
    global alfa_is_higher_than_12
    global beta_is_higher_than_12

    secondary_function()

    if alfa_is_higher_than_12=="yes":
        print("alfa is higher than 12")
    else:
        print("alfa isn't higher than 12")

    if beta_is_higher_than_12=="yes":
        print("beta is higher than 12")
    else:
        print("beta isn't higher thant 12")

main_function()

Answer 1

有人可能会问有什么原因可能需要像这样构造代码，但假设您有自己的原因，您可以只从辅助函数中返回值:

def secondary_function():

  alfa = 12
  beta = 5

  if alfa > 10:
      alfa_is_higher_than_12 = "yes"
  else:
      alfa_is_higher_than_12 = "no"

  if beta > 10:
      beta_is_higher_than_12 = "yes"
  else:
      beta_is_higher_than_12 = "no"

  return alfa_is_higher_than_12, beta_is_higher_than_12


def main_function():

  alfa_is_higher_than_12, beta_is_higher_than_12 = secondary_function()

  if alfa_is_higher_than_12=="yes":
      print("alfa is higher than 12")
  else:
      print("alfa isn't higher than 12")

  if beta_is_higher_than_12=="yes":
      print("beta is higher than 12")
  else:
      print("beta isn't higher thant 12")