Stubbing out functions or classes

python stub stubbing
xralf picture xralf · Oct 1, 2011 · Viewed 19.8k times · Source

Can you explain the concept stubbing out functions or classes taken from this article?

class Loaf:
    pass

This class doesn't define any methods or attributes, but syntactically, there needs to be something in the definition, so you use pass. This is a Python reserved word that just means “move along, nothing to see here”. It's a statement that does nothing, and it's a good placeholder when you're stubbing out functions or classes.`

thank you

Answer

Winston Ewert picture Winston Ewert · Oct 1, 2011

stubbing out functions or classes

This refers to writing classes or functions but not yet implementing them. For example, maybe I create a class:

class Foo(object):
     def bar(self):
         pass

     def tank(self):
         pass

I've stubbed out the functions because I haven't yet implemented them. However, I don't think this is a great plan. Instead, you should do:

class Foo(object):
     def bar(self):
         raise NotImplementedError

     def tank(self):
         raise NotImplementedError

That way if you accidentally call the method before it is implemented, you'll get an error then nothing happening.

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