以下是一个示例，演示了如何引用不同作用域和命名空间，以及 global 和 nonlocal 如何影响变量绑定: def scope_test():
def do_local():
spam = "local spam"
def do_nonlocal():
nonlocal spam
spam = "nonlocal spam"
def do_global():
global spam
spam = "global spam"
spam = "test spam"
do_local()
print("After local assignment:", spam)
do_nonlocal()
print("After nonlocal assignment:", spam)
do_global()
print("After global assignment:", spam)
scope_test()
print("In global scope:", spam)
以上示例代码的输出为: After local assignment: test spam
After nonlocal assignment: nonlocal spam
After global assignment: nonlocal spam
In global scope: global spam
注意：local 赋值语句是无法改变 scope_test 的 spam 绑定。nonlocal 赋值语句改变了 scope_test 的 spam 绑定，并且 global 赋值语句从模块级改变了 spam 绑定。 你也可以看到在 global 赋值语句之前对 spam 是没有预先绑定的。 |
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