What methods of implementing context managers in Python do you know?

In Python, there are two main ways to implement context managers:

1. Using __enter__ and __exit__ methods in a class

   You need to define a class with methods:

   • __enter__(self) — called when entering the with block, returns an object that will be assigned to the variable after as.
   • __exit__(self, exc_type, exc_val, exc_tb) — called when exiting the block, where you can handle exceptions and free resources.

   Example:

   class MyContext:
       def __enter__(self):
           print('Enter')
           return self
       def __exit__(self, exc_type, exc_val, exc_tb):
           print('Exit')
   
   with MyContext() as ctx:
       print('Inside block')
   

2. Using the @contextmanager decorator from the contextlib module

   Allows writing a generator where code before yield is the entry code, and code after yield is the exit code.

   Example:

   from contextlib import contextmanager
   
   @contextmanager
   def my_context():
       print('Enter')
       yield
       print('Exit')
   
   with my_context():
       print('Inside block')
   

Both methods are widely used in Python for resource management, such as working with files, locks, network connections, etc.