if __name__ == "__main__"如何正确理解

if name == "main"如何正确理解

粗略来讲，__name__是当前模块，当模块被直接运行时模块名为__main__。这句话的意思是，当模块被直接执行时，代码将运行，当模块是被导入时，代码不被运行

例如，执行one.py

 1 # file one.py
 2 def func():
 3     print("func() in one.py")
 4 
 5 print("top-level in one.py")
 6 
 7 if __name__ == "__main__":
 8     print("one.py is being run directly")
 9 else:
10     print("one.py is being imported into another module")

　　运行结果：

　　执行two.py:

1 # file two.py
2 import one
3 
4 print("top-level in two.py")
5 one.func()
6 
7 if __name__ == "__main__":
8     print("two.py is being run directly")
9 else:

　　运行结果：