python中if __name__ == '__main__'是什么意思

执行当前文件中： __name__ == '__main__' 是返回true，引用模块中的则返回false

如：现在有两python文件，one.py 和 two.py

# file one.py
def func():
    print("func() in one.py")

print("top-level in one.py")

if __name__ == "__main__":
    print("one.py is being run directly")
else:
    print("one.py is being imported into another module")

# file two.py
import one

print("top-level in two.py")
one.func()

if __name__ == "__main__":
    print("two.py is being run directly")
else:
    print("two.py is being imported into another module")