CODEWITHSUNDEEP
pythondictionarytypesisinstance
Stephen K
Stephen K

Reputation: 737

How to tell if a variable is a specific type of dictionary? i.e. dict(int, str)

I have a dictionary -

d = dict(
    0='a',
    1='b',
    2='c'
)

How can I tell if d is a dict of type (int, str)?

In C# it'd be something like:

d.GetType() == typeof(Dictionary<int, string>)

Upvotes: 0

Views: 182

Answers (3)

Sam Mason
Sam Mason

Reputation: 16184

if you're using Python 3.7 you can do something like:

from typing import Dict

d: Dict[int, str] = { 0: 'a', 1: 'b', 2: 'c' }

print(__annotations__['d'])

and get back: typing.Dict[int, str]

there's a function typings.get_type_hints that might be useful in the future, but currently only knows about objects of type:

function, method, module or class

PEP-0526 also says something is to be done about this

Upvotes: 0

Batman
Batman

Reputation: 8927

Python dictionaries don't have types. You'd literally have to check every key and value pair. E.g.

all(isinstance(x, basestring) and isinstance(y, int) for x, y in d.items())

Upvotes: 2

jpp
jpp

Reputation: 164683

Within a single Python dictionary, values may be of arbitrary types. Keys have the additional requirement that they must be hashable, but they may also cover multiple types.

To check keys or values in a dictionary are of a specific type, you can iterate them. For example:

values_all_str = all(isinstance(x, str) for x in d.values())
keys_all_int = all(isinstance(x, int) for x in d)

Upvotes: 1

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