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@rochacbruno
Last active July 5, 2023 10:56
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Use of __main__.py

The use of __main__.py to create executables

myprojectfolder/
    |_ __main__.py
    |_ __init__.py

Being __main__.py:

print("Hello")

if you do

python myprojectfolder
Hello

it can also work in submodules if you have a subfolder just use the dot python myprojectfolder.subfolder and the __main__.py inside that folder will be executed

Python will execute the code in __main__.py as this file is an entry point.

You can also zip the folder

 python -m zipfile -c myproject.zip myprojectfolder

YES Python can Zip files and folders!

and now you can get rid of myprojectfolder source code and run

python myproject.zip

YES! Python can execute zipped files (remember the .egg)

also you can easily obfuscate it and turn in to a binary like program

echo '#!/usr/bin/env python' >> myprogram
cat myproject.zip >>myprogram
chmod +x myprogram

Now you can delete myproject.zip and run

./myprogram

Sometimes it is better than the hackkish if __name__ == "__main__"

as seen on https://www.youtube.com/watch?v=0oTh1CXRaQ0

@EmbraceLife
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Great stuff! Thanks!

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ghost commented Nov 15, 2018

Hi, This may seem to be silly question. But I am curious to know why developers/programmers are not including main function in their code when they push it to a git repository? Is there any specific reason for it?

@MarkMichon1
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This was helpful! Thank you.

@RogerWebb
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I've run into a problem where there doesn't seem to be any way (other than manually hacking the path) to expose the other code in the module to main.py from init.py. Relative imports fail. Any tips?

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