[el_programmador]

The difference is that you've encapsulated your coding logic in mainMethod() instead of writing under that if condition itself. If latter was the case, you can't call that code from another module without resorting to os shell level features.

[Nginx487]

The code encapsulated into "__main__" assumed to be module-specific, this is the purpose of that pattern. If you want to make some code available for another module, you just refactor it into separate function.