Manual file closure, as well as leaving the closing responsibility to the execution environment, have one significant drawback. If an error occurs between opening a file for writing and closing it:
- In the best-case scenario, the file will remain open for too long, but a reference may still exist
- In the worst case, we may lose some data
It is desirable to automatically close the file immediately after finishing work with it, and even in case of an error. File objects can already work in this mode, but we should use them as context managers.
What are context managers
A context manager is an object that implements the corresponding protocol (yes, protocols everywhere!). Objects that implement this protocol allow the use of the following special syntax: