Question

Python’s setdefault allows you to get a value from a dictionary, but if the key doesn’t exist, then you assign the based on parameter default. You then fetch whatever is at the key in the dictionary.

Without manipulating an object’s __dict__Is there a similar function for objects?

e.g.

I have an object foo which may or may not have attribute bar. How can I do something like:

result = setdefaultattr(foo,'bar','bah')

Answer 1

Python doesn’t have one built in, but you can define your own:

def setdefaultattr(obj, name, value):
    if not hasattr(obj, name):
        setattr(obj, name, value)
    return getattr(obj, name)