Freeze

Freeze introduces 3 frozen collections: FDict, FSet and FList. They are immutable, hashable, support type-hinting, and will attempt to recursively convert mutable collections into frozen counterparts on initialization.

Motivation

While there are built-in immutable versions for list (tuple) and set (frozenset), they have some issues:

tuple can store mutable objects so its immutability is not guaranteed.
frozenset can't be initialized with mutable objects.
dict doesn't have a built-in immutable version at all.

Installation

pip install frz

Usage

from freeze import FDict, FList, FSet

a_mutable_dict = {
    "list": [1, 2],
    "set": {3, 4},
}

a_frozen_dict = FDict(a_mutable_dict)

print(repr(a_frozen_dict)) # FDict: {'list': FList: (1, 2), 'set': FSet: {3, 4}}

How Freeze Works

Freezing a collection is achieved by following the following logic recursively:

Immutable objects (except for collections) stay the same.
Mapping (e.g. dict) frozen with FDict.
Sequence (e.g. list or tuple) frozen as FLists.
AbstractSet (e.g. set) frozen as FSets.
If any value in the collection can't be frozen, an exception is raised.

Known Issues:

Type hints are only accurate as long as no data conversion was performed.

Future Plans:

support for thawing frozen collections.
support for freezing more mutable types.