Not having to rewrite 'obj.' on each line

[micseydel]

You can do something terrible like this

from copy import copy

class Greeter:
    def __init__(self, to):
        self.to = to

    def hello(self):
        return "Hello, {}!".format(to)

class Magic:
    def __init__(self, instance, enclosing_locals):
        self.instance = instance
        self.enclosing_locals = enclosing_locals
        self.origin_enclosing_locals = copy(enclosing_locals)

    def __enter__(self):
        for key in dir(self.instance):
            self.enclosing_locals[key] = getattr(self.instance, key)

    def __exit__(self, type, value, traceback):
        for key in list(self.enclosing_locals.keys()):
            del self.enclosing_locals[key]

        self.enclosing_locals.update(self.origin_enclosing_locals)

with Magic(Greeter("world"), locals()):
    print(hello())

I bet there's a way to not require the locals() call but I couldn't figure it out in a few minutes' Googling. Note that I'm messing with scopes such that any new variables defined within the with-block which would normally be available after the block, won't be. Anyone familiar with Python reading your code would be confused unnecessarily.