Access a function variable outside the function without using "global"

The problem is you were calling print(x.bye) after you set x as a string. When you run x = hi() it runs hi() and sets the value of x to 5 (the value of bye; it does NOT set the value of x as a reference to the bye variable itself). EX: bye = 5; x = bye; bye = 4; print(x) prints 5, not 4.

Also, you don't have to run hi() twice, just run x = hi(), not hi(); x=hi() (the way you had it it was running hi(), not doing anything with the resulting value of 5, and then rerunning the same hi() and saving the value of 5 to the x variable.

So full code should be

def hi():
    bye = 5
    sigh = 10
    return bye 
x = hi()
print(x)

If you wanted to return multiple variables, one option would be to use a list, or dictionary, depending on what you need. For example:

def hi():
    return { 'bye': 5, 'sigh': 10 }
x = hi()
print x['bye']

You could do something along these lines (which worked in both Python v2.7.17 and v3.8.1 when I tested it/them):

def hi():
    # other code...
    hi.bye = 42  # Create function attribute.
    sigh = 10

hi()
print(hi.bye)  # -> 42

Functions are objects in Python and can have arbitrary attributes assigned to them.

If you're going to be doing this kind of thing often, you could implement something more generic by creating a function decorator that adds a this argument to each call to the decorated function.

This additional argument will give functions a way to reference themselves without needing to explicitly embed (hardcode) their name into the rest of the definition and is similar to the instance argument that class methods automatically receive as their first argument which is usually named self — I picked something different to avoid confusion, but like the self argument, it can be named whatever you wish.

Here's an example of that approach:

def add_this_arg(func):
    def wrapped(*args, **kwargs):
        return func(wrapped, *args, **kwargs)
    return wrapped

@add_this_arg
def hi(this, that):
    # other code...
    this.bye = 2 * that  # Create function attribute.
    sigh = 10

hi(21)
print(hi.bye)  # -> 42

Note

This doesn't work for class methods. Just use the instance argument, named self by convention, that's already passed to methods instead of the method's name. You can reference class-level attributes through type(self). See Function's attributes when in a class.