Any simple python package providing dict merge?

Question

I want to do something like this:

merge({'a': 1}, {'b': 2})

and get a return of {'a': 1, 'b':2}.

1. I don't want to use .update(), which sadly doesn't return the updated or a new dict, just None (why?.....).
2. Since I know .update(), I could write a 3 line function for this. I don't, I just want an already existing/known package that do this kind of job in a simple way.

EDIT

This edit is just to explain the lovely SO users that this is not a duplicate of How to merge two Python dictionaries in a single expression? and hence the chosen answer is unrelated with any of the answers provided in the candidate duplicate.

Answer 1

The package dictmerge can merge dictionaries.

As of Python 3.5 you can merge dictionaries without an additional package:

>>> d1 = {'a': 1}
>>> d2 = {'b': 2}
>>> {**d1, **d2}
{'b': 2, 'a': 1}

Answer 2

In Python 2.7, you can one-line (ignoring imports) a merge with:

from itertools import chain

merged = dict(chain(dict1.viewitems(), dict2.viewitems()))

In Py3.5 and higher, you can use additional unpacking generalizations to do this without any functions at all:

merged = {**dict1, **dict2}

The reason dict.update returns None is because Python methods, as a general rule, stick to either mutating an existing object or returning a new object, not both. Basically, functions with side-effects aren't supposed to be used in a functional manner (because it's liable to confuse).

Answer 3

d1 = {'a': 1}
d2 = {'b': 2}

d3 = dict(d1, **d2)

As ShadowRanger points out in the comments, this only works if all keys of d2 are of type str.