Shortest way of creating an object with arbitrary attributes in Python?

Question

Hey, I just started wondering about this as I came upon a code that expected an object with a certain set of attributes (but with no specification of what type this object shoul

Answer 1

This is typically something you would use a dict for, not making a class at all.

Answer 2

type('', (), {})() will create an object that can have arbitrary attributes.

Example:

obj = type('', (), {})()
obj.hello = "hello"
obj.world = "world"
print obj.hello, obj.world #will print "hello world"

type() with three arguments creates a new type.

The first argument '' is the name of the new type. We don't care about the name, so we leave it empty.

The second argument () is a tuple of base types, here object (implicit).

The third argument is a dictionary of attributes of the new object - again we don't care to it's an empty dictionary {}

And in the end we instantiate a new instance of this new type with () at the end.

Answer 3

If you don't need to pass values in the constructor, you can do this:

class data: pass

data.foo = 1
data.bar = 2

You use the class static member variables to hold your data.

Answer 4

A function is an object. So you could assign attributes to a function. Or make one. This is the simplest way in terms of lines of code, I think.

def hello():
    pass


hello.chook = 123

but the easiest and most elegant way (but Python 3.3+) is to use the standard libary's SimpleNamespace:

>>> from types import SimpleNamespace
>>> foo = SimpleNamespace()
>>> foo.hello = "world"

Answer 5

If I understand your question correctly, you need records. Python classes may be used this way, which is what you do.

I believe the most pythonic way of dealing with "records" is simply... dictionaries! A class is a sort of dictionary on steroids.

Your class example data is essentially a way of converting a dictionary into a class.

(On a side note, I would rather use self.__setattr__(name, kw[name]).)