Assign contents of Python dict to multiple variables at once?

Question

I would like to do something like this

def f():
    return { 'a' : 1, 'b' : 2, 'c' : 3 }

{ a, b } = f()     # or { 'a', 'b' } = f() ?

I.e. so that a gets assigned 1, b gets 2, and c is undefined

This is similar to this

def f()
    return( 1,2 )

a,b = f()

Answer 1

It wouldn't make any sense for unpacking to depend on the variable names. The closest you can get is:

a, b = [f()[k] for k in ('a', 'b')]

This, of course, evaluates f() twice.

---

You could write a function:

def unpack(d, *keys)
    return tuple(d[k] for k in keys)

Then do:

a, b = unpack(f(), 'a', 'b')

---

This is really all overkill though. Something simple would be better:

result = f()
a, b = result['a'], result['b']

Answer 2

Hmm. Kind of odd since a dictionary is not ordered, so the value unpacking depends on the variable names. But, it's possible, if ugly:

>>> locals().update(f())
>>> a
1

Don't try this at home! It's a maintainability nightmare. But kinda cool too :-)