zipfile64

Adds Deflate64 support to Python's standard zipfile module.

Features

• reads ZIP archives that use compression method 9 (Deflate64)
• writes ZIP archives with Deflate64 when requested
• keeps the standard zipfile API
• uses uv for dependency and virtualenv management

Getting started

Example using pip:

pip install zipfile64

Usage

# Importing zipfile64.zipfile will patch the built-in zipfile module
import zipfile64.zipfile as zipfile


with zipfile.ZipFile("archive.zip") as zf:
	print(zf.namelist())
	data = zf.read("example.txt")

Writing a Deflate64 archive:

import io
import zipfile

from zipfile64 import ZIP_DEFLATE64, patch

patch()

buffer = io.BytesIO()
with zipfile.ZipFile(buffer, mode="w", compression=ZIP_DEFLATE64) as zf:
	zf.writestr("hello.txt", b"hello world")

You can also use the patched python zipfile CLI:

• uv run zipfile64 -l archive.zip
• uv run zipfile64 -e archive.zip output-dir

Development

Create the virtual environment and install dependencies with uv:

• uv sync
• uv sync --group dev for test dependencies

uv will create the local virtual environment for the project.

• uv run pytest

Limitations

• patching is process-wide because it extends the standard-library module
• Deflate64 compression level is currently ignored by the backend library