How to use `if __name__ == '__main__'` statement in Python

The if __name__ == '__main__' statement in Python is commonly used to ensure that the code within this block is only executed if the script is run directly, as opposed to being imported as a module or package by another script.

When you run a Python script, the interpreter sets the __name__ variable to "__main__" if the script is being executed as the main program. This provides a way for scripts to know whether they are being run directly or being imported as a module.

The if __name__ == '__main__' statement is typically used to define and execute some initial setup and then start running the main logic of the program. For example, it can be used to define global variables or classes, initiate a database connection, or start a web server.

In summary, using if __name__ == '__main__' allows you to write code that can be executed as a standalone program, as well as being imported and used by other programs as a library.