Terminate importation of module non-fatally?

Question

I'd like use if __name__ != '__main__': and then end the execution of a script at that point when it's being imported, rather than doing the usual if __name__ == '__main__': and indentation of all the rest of the code in the file.

However I have been unable to determine what would cause only this to happen and not have other undesirable side-effects. sys.exit() stops the whole interpreter and all the other things I've tried either raise some sort of exception or are illegal.

Update:

I've selected @trutheality's answer because it accomplishes what I want and is extremely easy to start using. That said, I thought several of the other answers very interesting and/or clever -- thanks to all who responded -- and plan on investigating some of them further as time permits. I had no idea doing what I want could get so involved.

Answer 1

Another Hack:

# code

if __name__ == "__main__": exec("""

# main code

#""")

So... you've lost the indentation, but also the syntax highlighting and any other features of the editor you were using, unless you comment out the if line every time you edit.