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

The original code can be streamlined a little by using __dict__:

In [1]: class data:
   ...:     def __init__(self, **kwargs):
   ...:         self.__dict__.update(kwargs)
   ...: 

In [2]: d = data(foo=1, bar=2)

In [3]: d.foo
Out[3]: 1

In [4]: d.bar
Out[4]: 2

In Python 3.3 and greater, this syntax is made available by the types.SimpleNamespace class.

Answer 2

Use a combination between lambda and type build-in, I think is the smallest way to do that:

obj = lambda **kwargs: type('obj', (object,), kwargs)()

options = obj(do_good_stuff=True, do_bad_stuff=False)

print options.do_good_stuff
print options.do_bad_stuff

Answer 3

Use collections.namedtuple.

It works well.

from collections import namedtuple
Data = namedtuple( 'Data', [ 'do_good_stuff', 'do_bad_stuff' ] )
options = Data( True, False )

Answer 4

This is the shortest way I know

>>> obj = type("myobj",(object,),dict(foo=1,bar=2))
>>> obj.foo
1
>>> obj.bar
2
>>> 

using dict instead of {} insures your attribute names are valid

>>> obj = type("myobj",(object,),{"foo-attr":1,"bar-attr":2})
>>> obj.foo-attr
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: type object 'myobj' has no attribute 'foo'
>>>

Answer 5

You might be interested in the "Struct", which is part of the IPython package. It does what you want to do, with lots of useful methods.

http://ipython.org/ipython-doc/rel-0.13/api/generated/IPython.utils.ipstruct.html

Answer 6

This works in 2.5, 2.6, and 3.1:

class Struct(object):
    pass

something = Struct()
something.awesome = abs

result = something.awesome(-42)

EDIT: I thought maybe giving the source would help out as well. http://docs.python.org/tutorial/classes.html#odds-and-ends

EDIT: Added assignment to result, as I was using the interactive interpreters to verify, and you might not be.