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.