lambda赋值给全局变量? [英] lambda to assign a value to global variable?

问题描述

我正在使用tkinter并尝试在按下按钮时将值分配给全局变量.这是代码: popup.add_command(label="Allow Moving Item", command=lambda: allowMoving=True) 我收到无效的语法.你能告诉我如何解决这个问题吗? 非常感谢！

I'm using tkinter and trying to assign a value to a global variable on a button press. Here is the code: popup.add_command(label="Allow Moving Item", command=lambda: allowMoving=True) I'm getting the invalid syntax. Can you tell me how to work this around? Many thanks!

推荐答案

仅用于娱乐目的.

popup.add_command(label="Allow Moving Item",
                  command=lambda: globals().update(allowMoving=True))

(尽管记录的globals()没有与locals()相同的请勿修改返回值"警告，但我仍不确定这是否可以保证工作.)

(Although globals() is not documented with the same "do not modify the return value" warning as locals(), I'm still not sure this is guaranteed to work.)

一个更好的答案是改为使用def语句定义回调.

A better answer would be to define the callback with a def statement instead.

def set_allow_moving():
    global allow_moving    # Don't use camel case for variable names in Python
    allow_moving = True

popup.add_command(label="Allow Moving Item", command=set_allow_moving)

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