Python: Implement a custom context manager
source link: https://proinsias.github.io/til/python-implement-a-custom-context-manager/
Go to the source link to view the article. You can view the picture content, updated content and better typesetting reading experience. If the link is broken, please click the button below to view the snapshot at that time.
Francis T. O'Donovan
Senior Data Science Manager at Hospital IQ – Planet discoverer, researcher, developer, geek.
Python: Implement a custom context manager
less than 1 minute read
The context manager type is a Python feature to help work with unmanaged resources (e.g. file streams) which it is better to clean up or shutdown in an orderly manner after use, e.g. always closing a file after use).
The use of the with statement (on objects that support it, such as built-in or custom context managers) is used to ensure resources are cleaned up after use.
with
can be seen as syntactic sugar for thetry/except/finally
block.To implement a custom context manager, two methods must be implemented:
class my_context_manager: def __enter__(self): # set up things return thing def __exit__(self,type,value,traceback): # deal with unmanaged resources with my_context_manager as custom_name # work with resources
When the with statement is executed,
__enter__
is called, assigning the returned value to the variable after as.Whatever happens in the code, the
__exit__
method will be called in the end to make sure nothing is left unmanaged.
Via enkipro.com.
Categories: til
Updated: July 27, 2022
You May Also Enjoy
Recommend
About Joyk
Aggregate valuable and interesting links.
Joyk means Joy of geeK