Context Management

What are context managers?

The need to close files when we are finished with them can make our code quite ugly. Because an exception may occur at any time during file I/O, we ought to wrap all calls to a file in a try...finally clause. The file should be closed in the finally clause, regardless of whether I/O was successful. This isn’t very Pythonic. Of course, there is a more elegant way to do it.

Python’s file objects are also context managers. By using the with statement, the context management methods ensure that the file is closed, even if an exception is raised. By using the with statement, we no longer have to explicitly manage the closing of the file.