python - Why does it do this ? if - __name__ == '__main__'

Duplicate of:
What does if __name__== "__main__" do?

Consider this code:

if __name__ == '__main__':
    import pdb
    pdb.run("interact()\n")

What does the following line mean?

if(__name__=='__main__')

I fainted.

Answer

This will be true if this module is being run as a standalone program. That way, something can act either as a module imported by another program, or a standalone program, but only execute the code in the if statement if executed as a program.