Millised piirangud on dict võtmetele Pythonis?

In Python, keys in a dictionary (dict) must be hashable (immutable) objects. This means that keys must have an unchangeable state and implement the __hash__() method.

Main restrictions:

• Keys must be immutable types, for example: strings (str), numbers (int, float), tuples (tuple), provided all elements of the tuple are also hashable.
• Mutable types such as lists (list), sets (set), dictionaries (dict) cannot be used as keys because they are not hashable.

Example:

valid_dict = {
    "key": 1,
    42: "value",
    (1, 2): "tuple key"
}

invalid_dict = {
    [1, 2]: "list as key"  # will raise TypeError
}

Trying to use a mutable object as a key will cause Python to raise a TypeError: unhashable type error.