The function of double underscore back and front in a class function name?

[deanhystad]

Not quite. calculate_gas_milage() would try to call a function named calculate_gas_milage and return a result. This would either raise a NameError, or map "efficiency" to the result, not the function. More importantly, python knows that it needs to change instance.method(args) into insance.__class__.method(instance, args) when it is calling an instance method of a class. It would not know to do that if you just stuffed a function in a dictionary.

I'm occasionally tasked with maintaining Python projects that use dictionaries to mimic classes, even though Python always had classes. Let me just say that doing this is a bad idea and leave it at that. Shudder!