Uses of __name__ in Python

In our previous Python tutorial, we have explained about *Args and **Kwargs in Python. In this tutorial, we will explain about __name__ in Python.

We mostly see the __name__ variable liek below code when gone through the Python code. This is a special variable in Python that used to create modules.


if __name__ == '__main__':    
	main()

When we run Python script, the __name__ variable is always equals __main__ for that script.

So question arises, why and when we need to use this special variable in our code. Sometimes we write a script with functions that might be useful in other scripts as well. In Python, we can import that script as a module in another script.

With __name__ special variable, we can decide whether we want to run the script or want to import the functions defined in the script.

So let’s the scenarios of using the __name__ variable in our code:

Scenario 1: Execude If name Equals main

Here we have Python script script_1.py and define functions and caling within __name__ condition.

script_1.py:


def some_fun():
    print("I am handling a lot of functions!!!")


def main():
    some_fun()

if __name__ == '__main__':
     main()

When run above code, the __name__ variable is set to __main__. It is checking for __main__ in if condition. The if condition will be true here, the main() and then some_fun() statements will be called and print message .

Scenario 2: Importing Script AS Module

If we want to re-use some_fun() in another script, for example script_2.py, we can import script_1.py as a module.

script_2.py:


import script_1 as scr

scr.some_fun()

Here we have two scope. In script_2.py, the __name__ variable is set to __main__. We have imported script_1.py as module and called some_fun() from module. When we run the above code, the def statement for main() and some_fun() will be run. But the condition will evaluate to false and main is not called.

As we have called some_fun() in script_2.py which output script_1.py because it is known to that function when the function was defined.

Conclusion

In this tutorial, we have explained how you can use the __name__ variable in different scenarios to write code. Hope you have enjoyed this tutorial and try same at your end. Cheers!

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