Python frozenset
frozenset is an immutable version of a set.
Like sets, it contains unique, unordered, unchangeable elements.
Unlike sets, elements cannot be added or removed from a frozenset.
Creating a frozenset
Use the frozenset() constructor to create a frozenset from any iterable.
Example
x = frozenset({"apple", "banana", "cherry"})
print(x)
print(type(x))
Frozenset Methods
Being immutable means you cannot add or remove elements. However, frozensets support all non-mutating operations of sets.
| Method | Shortcut | Description | Try it |
|---|---|---|---|
| copy() | Returns a shallow copy | ||
| difference() | - |
Returns a new frozenset with the difference | |
| intersection() | & |
Returns a new frozenset with the intersection | |
| isdisjoint() | Returns True if there is NO intersection between two frozensets | ||
| issubset() | <= / < |
Returns True if this frozenset is a (proper) subset of another | |
| issuperset() | >= / > |
Returns True if this frozenset is a (proper) superset of another | |
| symmetric_difference() | ^ |
Returns a new frozenset with the symmetric differences | |
| union() | | |
Returns a new frozenset containing the union |
