General Information

Many python source files will have an interesting if statement around main(). This is why it exists.

Checklist

• Python versions: 2 and 3

if __name__ == '__main__':
  main()

It may include other statements as well.

This special if statement is checked by the python interpreter itself when it reads the source file.

• If the source is being run as the main program, it sets that source file as the special “name” variable to “main”.
• If the source file is being imported from another module, the “name” variable will be set to the module's name instead.

The entire reason behind this is:

• Sometimes modules are written to be executed directly.
• They could also be imported for use in another module.
• The main check allows for only the “main” code to execute if run directly and not if someone imports the module to call functions.