python - 如何在 Python 中访问类内的全局变量

Question

我有这个:

g_c = 0

class TestClass():
    global g_c
    def run(self):
        for i in range(10):
            g_c = 1
            print(g_c)

t = TestClass()
t.run()

print(g_c)

我怎样才能真正修改我的全局变量 g_c？

Answer 1

通过在访问它的函数中声明它global:

g_c = 0

class TestClass():
    def run(self):
        global g_c
        for i in range(10):
            g_c = 1
            print(g_c)

Python documentation关于 global 声明这样说的:

The global statement is a declaration which holds for the entire current code block.