I've been playing mostly with PHP and Python.
I've been reading about Interfaces in OO programming and can't see an advantage in using it.
Multiple objects can implement the same interface, but multiple inheritance doesn't provide this as well?
Why do I need to create an Interface "with no implementation" - mainly a "contract" - if I can just check if a method exists in an object in Python, that inherits from multiple classes?
Do Interfaces were created in another languages because they don't provide multiple inheritance? Or am I missing something more important here?
It's generally implemented to replace multiple inheritance (C#). 
I think some languages/programmers use them as a way of enforcing requirements for object structure as well.
Are Interfaces just "Syntactic Sugar"?