#TIL : Context Managers in Python

Jul 24, 2018 4 mins read

Context Managers in Python

In Python, sometimes you will see this syntax

with something:
    do_something_else(something)

Then you ask yourself, why I have to use this with syntax ? What runs inside that statement ?

Here is how it works, it’s called Context Managers in object

You can define context managers for a class of object to make sure some logic runs correctly without forgeting

Example :

class Animal:
    def __init__(self, name):
        self.name = name
    
    def __enter__(self):
        print("Enter the room !")
    
    def __exit__(self, exc_type, exc_value, traceback):
        print("Exit the room !")

kitty = Animal("Kitty Kat")
with kitty:
    print(kitty.name)

Result

Enter the room !
Kitty Kat
Exit the room !

So, when you start using with keyword on a object, it runs __enter__ method, when everything inside with block is runned, __exit__ will be called !

It’s cool feature of Python !

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