Python's __file__ and __name__ variables

#现在的目录结构为

To invoke a method in the web3/main.py module #现在想要在web2/bin.py

 from Import Mainmain.foo () # Execute in Pycharm # ####### OK # Execute in CMD # ####### ' web3 '

#发现在pycharm中执行与在cmd中执行的结果不同 (the path to the project directory Web1 is not found in cmd), because Pycharm automatically writes the path of the project to the environment variable in python

ImportSYSPrint(Sys.path)#Execute in Pycharm#######['E:\\9--PYTHON\\WEB1\\WEB2','E:\\9--python\\web1','E:\\9--python\\web1\\venv\\scripts\\python36.zip','D:\\python3\\dlls','D:\\python3\\lib','D:\\python3','e:\\9--python\\web1\\venv','e:\\9--python\\web1\\venv\\lib\\site-packages','E:\\9--python\\web1\\venv\\lib\\site-packages\\setuptools-28.8.0-py3.6.egg','E:\\9--python\\web1\\venv\\lib\\site-packages\\pip-9.0.1-py3.6.egg','d:\\pycharm 2017.3.4\\helpers\\pycharm_matplotlib_backend']#Execute in CMD########['E:\\9--PYTHON\\WEB1\\WEB2','D:\\python3\\python36.zip','D:\\python3\\dlls','D:\\python3\\lib','D:\\python3','d:\\python3\\lib\\site-packages']

#所以如果想要使得在任何环境下代码都可执行的话, just manually import the project's path into the environment variable path, which requires __file__.

#变量__file__表示文件本身, the output is an absolute path (but the absolute path is automatically output in pycharm), so it needs to be converted to an absolute path

 print  (__file__  )  #   execute in Pycharm  #  #######  e:/9--python/python_ Project/web1/web2/bin.py  #   execute  #  #######  bin.py 

Import SYS Import osdir_name=os.path.dirname (Os.path.dirname (Os.path.abspath (__file__)))Print  (dir_name) sys.path.append (dir_name)########E:\9--python\web1

The method of calling web3/main.py #现在在cmd中先要从web2/bin.py can be implemented.

#所以在pycharm中编程, you need to be aware of some of the elegant actions that you can make to prevent code from executing in another environment

#在编程过程中, it is unavoidable to test the link, so now in web3/main.py want to test whether the Foo () function can execute, then it should be called in. However, if you now import the module main.py from web2/bin.py, the Foo () method used for the test will be executed

# in the web3/main.py def foo ():     Print ('ok') foo () # #######OK

# in the web2/bin.py  from Import Mainmain.foo () # ####### Okok

#所以如果想要解决这个问题, you need the __name__ variable, now look at the difference between the __name__ variable being executed in the script itself and the execution being invoked

# in the web3/main.py def Bar ():     Print (__name__) bar () #  __main__

# in the web2/bin.py  from Import Mainmain.bar () # ####### Web3.mainweb3.main

#发现在脚本本身执行的话其输出为__main__, the name of the original script is output when it is invoked

#所以可以在脚本的逻辑代码前加一句判断 so that the invocation is not the logical code that executes the original script, only the method is allowed to be called

if __name__ ' __main__ ' :    Logical Code

Python's __file__ and __name__ variables