Do OO design principles apply to Python?

Question

It seems like many OO discussions use Java or C# as examples (e.g. Head First Design Patterns).

Do these patterns apply equally to Python? Or if I follow the design pat

Answer 1

Python has it's own design idioms. Some of the standard patterns apply, others don't. Something like strategy or factories have in-language support that make them transparent.

For instance, with first-class types anything can be a factory. There's no need for a factory type, you can use the class directly to construct any object you want.

Basically, Python has its own design idioms that are somewhat different largely because it's so dynamic and has incredible introspection capabilities.

Example:

x = list
my_list = x(range(0,5)) #creates a new list by invoking list's constructor

By assigning the class-type to a callable object you can essentially remove any 'factory' types in your code. You are only left with callables that produce objects that should conform to some given conventions.

Furthermore, there are design patterns in Python that just can't be represented in other statically-typed languages efficiently. Metaclasses and function decorators are good examples of this.