====== if __name__ main ======

**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

----

====== The Code ======

<code python>
if __name__ == '__main__':
  main()
</code>

===== Explanation =====

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.