Advanced Python syntax - private property -with context manager (4.7.3)

@

1. Description

Manager context
used here with open operating files, so the file object implements the automatic release of resources. We can also customize the context manager by __enter __ () and __exit __ () method of operation of these two magic file from defined
when there is a scene context of use, such as open a thing to be shut down, files and other resources such as , can be used in this manner to define a context manager

2. Code

class File():
    def __init__(self,filename,mode):
        self.filename  = filename
        self.mode = mode

    def __enter__(self):
        print("__enter__")
        self.f = open(self.filename,self.mode,encoding="utf-8")
        return self.f

    def  __exit__(self, exc_type, exc_val, exc_tb):
        print("__exit__")
        self.f.close()


with File("魔方方法.py","r") as f:
    print(f.read())

About the Author

Personal blog site
personal GitHub address
individual public number: