If a class has a close() or similar method to release resources, then it should be made a context manager. Using a context manager allows instances of the class to be used in the with statement, improving code size and readability. This is a simpler and more reliable method than implementing just a __del__ method.

The context manager requires an __enter__ and an __exit__ method:

__enter__ method acquires the resource or does nothing if the resource is acquired in the __init__ method
__exit__ method releases the resource, this can just be a simple wrapper around the close method.

The following example shows how a class definition that implements __del__ can be updated to use a context manager.

Effbot: Python with statement.

Python Standard Library: Context manager .

Python Language Reference: With Statement Context Managers.

Python PEP 343: The "with" Statement.