frozenlist

library1.8.0pypypi✓ verified 31d ago

FrozenList is a Python library providing a list-like structure that implements collections.abc.MutableSequence. The list remains mutable until the freeze() method is called, after which any modifications raise a RuntimeError. The current version is 1.8.0, released in October 2025, with a release cadence of approximately one to two updates per year.

data

pip install frozenlist

github ↗package ↗

INSTALL

IMPORT

SIG · FROZENLIST

frozenlist

datapythonv1.8.0

Install

1.9s avg

Import

10ms

Disk

16MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.8.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

installs and imports cleanly · install 0.0s · import 0.000s · 18.3MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 1.9s · import 0.002s · 19MB

16MB installed

● package 16MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

FrozenList

✓ from frozenlist import FrozenList

Demonstrates creating a FrozenList, modifying it, freezing it, and handling attempts to modify it after freezing.

from frozenlist import FrozenList # Create a mutable FrozenList fl = FrozenList([1, 2, 3]) fl.append(4) print(fl) # Output: [1, 2, 3, 4] # Freeze the list fl.freeze() # Attempting to modify the frozen list raises RuntimeError try: fl.append(5) except RuntimeError as e: print(e) # Output: Cannot modify frozen list.

Debug

Known issues

breakingDropped support for Python 3.7 in version 1.4.0.

fix

Upgrade your Python environment to version 3.8 or newer.

affects: >=1.4.0

breakingDropped support for Python 3.6 in version 1.3.0.

fix

Upgrade your Python environment to version 3.7 or newer.

affects: >=1.3.0

gotchaAttempting to modify a FrozenList after calling freeze() raises a RuntimeError.

fix

Ensure that all necessary modifications are made before freezing the list.

affects: All versions

gotchaA FrozenList instance is hashable only when frozen; attempting to hash a non-frozen instance raises a RuntimeError.

fix

Call freeze() before attempting to hash a FrozenList instance.

affects: All versions

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'frozenlist'

The 'frozenlist' package has not been installed in the Python environment you are using.

fix

Install the package using pip: `pip install frozenlist`

RuntimeError: Cannot modify frozen list.

You attempted to modify a FrozenList instance after its `freeze()` method has been called, rendering it immutable.

fix

Ensure modifications are made before calling `freeze()`, or create a new FrozenList instance if further modifications are required.

ERROR: Could not build wheels for frozenlist, which is required to install pyproject.toml-based projects.

This error typically occurs during installation, often when Python cannot compile the underlying C extensions of 'frozenlist', sometimes due to missing build tools (like `gcc`) or compatibility issues with newer Python versions (e.g., Python 3.11, 3.12) that might require a more recent 'frozenlist' version or specific compiler flags.

fix

Ensure your build tools (like `gcc`) are installed and up-to-date. If using a newer Python version, try upgrading `pip` and `setuptools` (`pip install --upgrade pip setuptools`) or check if a newer 'frozenlist' version with pre-built wheels for your Python version is available.

Upgrade

Version history

1.8.0latest on PyPI · released Oct 6, 2025

Audit

Dependencies

No dependency data recorded yet.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/aio-libs/frozenlist ↗

packagehttps://pypi.org/project/frozenlist/ ↗