这是两种实现相同目的的方法：
使用参数并返回（推荐）
def other_function(parameter): return parameter + 5def main_function(): x = 10 print(x) x = other_function(x) print(x)
运行时
main_function，将获得以下输出
>>> 10>>> 15
使用全局变量（永远不要这样做）
x = 0 # The initial value of x, with global scopedef other_function(): global x x = x + 5def main_function(): print(x) # Just printing - no need to declare global yet global x # So we can change the global x x = 10 print(x) other_function() print(x)
现在您将获得：
>>> 0 # Initial global value>>> 10 # Now we've set it to 10 in `main_function()`>>> 15 # Now we've added 5 in `other_function()`
