Python: create dictionary using dict() with integer keys?

Question

In Python, I see people creating dictionaries like this:

d = dict( one = 1, two = 2, three = 3 )

What if my keys are integers? When I try this:

Answer 1

Yes, but not with that version of the constructor. You can do this:

>>> dict([(1, 2), (3, 4)])
{1: 2, 3: 4}

There are several different ways to make a dict. As documented, "providing keyword arguments [...] only works for keys that are valid Python identifiers."

Answer 2

a = dict(one=1, two=2, three=3)

Providing keyword arguments as in this example only works for keys that are valid Python identifiers. Otherwise, any valid keys can be used.

Answer 3

There are also these 'ways':

>>> dict.fromkeys(range(1, 4))
{1: None, 2: None, 3: None}
>>> dict(zip(range(1, 4), range(1, 4)))
{1: 1, 2: 2, 3: 3}