A dictionary key accepts `int`, `float`, `complex`, `bool` and a tuple

[hyperkai]

Bug report

Bug description:

I don't know if it's bug or not. A dictionary key accepts int, float, complex, bool and a tuple as shown below:

v = {2:3, 2.3:4.5, 2.3+4.5j:6.7+8.9j, True:False, (2, 3):(4, 5)}

print(v[2], v[2.3], v[2.3+4.5j], v[True], v[(2, 3)])
# 3 4.5 (6.7+8.9j) False (4, 5)

In addition, a dictionary key doesn't accept a list, set and dictionary as shown below:

v = {[2, 3]:[4, 5]}

print(v[[2, 3]]) # TypeError: unhashable type: 'list'

v = {{2, 3}:{4, 5}}

print(v[{2, 3}]) # TypeError: unhashable type: 'set'

v = {{'a':'b'}:{'c':'d'}}

print(v[{'a':'b'}]) # TypeError: unhashable type: 'dict'

CPython versions tested on:

3.12

Operating systems tested on:

Windows

[skirpichev]

I don't know if it's bug or not.

It's not. Any hashable key is acceptable.

In addition, a dictionary key doesn't accept a list, set and dictionary as shown below:

Docs says:

A dictionary’s keys are almost arbitrary values. Values that are not hashable, that is, values containing lists, dictionaries or other mutable types (that are compared by value rather than by object identity) may not be used as keys.

Maybe it's a good idea if you next time open instead a thread in "help" category of https://discuss.python.org/