if __name__ == '__main__':

Question

I can't understand it.Please someone explain it step by step.

Answer 1

Here __main__ is just a string that is used to check if the current module/script is running on its own or not. In the __name__ variable, the double underscores on both sides of name is for indicating the python interpreter to recognize it as a special/reserved keyword.

Some resources to understand better:

1 - What does the if __name__ == “__main__”: do?

https://www.geeksforgeeks.org/what-does-the-if-__name__-__main__-do/

2 - Python if __name__ == __main__ Explained with Code Examples

https://www.freecodecamp.org/news/if-name-main-python-example/

3 - __main__ — Top-level script environment

https://docs.python.org/3/library/__main__.html

4 - https://www.studytonight.com/python/_name_-as-main-method-in-python

Answer 2

that's a conditional statement wich will run the next indented block only if the script is running at first one (not if imported as module)...