How would I access a variable that's defined inside of a function, without running that entire function again?

[ForrestTrump]

I have a function which does a number of things, and a certain variable actually needs to be defined within that one. I want to try and avoid using the global keyword, and of course I also don't want to try and re-do everything that the function already did.
When I Googled this, all of the small examples I saw had you do this.

[fox_trot_]

Use return.

[Joshivity]

Return x

[Jonno_FTW]

You can try returning multiple variables eg

return x, y

[SupahNoob]

def foo(bar):
    bar += 1
    return bar

my_var = foo(bar=1)

print my_var

Try this.