Master Python Zipfile: Read, Extract, and Create ZIP Archives Efficiently

Most people are familiar with the .zip format, which bundles multiple files into a single archive for easier transmission and storage.

This article shows how to work with ZIP files in Python using the built‑in zipfile module.

1. Read ZIP File Information

To inspect a ZIP archive you first create a ZipFile object, similar to a regular file object.

import zipfile
zip_file = zipfile.ZipFile('zfile.zip')
# List all entries in the archive
f_content = zip_file.namelist()
# Size before compression
f_size = zip_file.getinfo('zfile/a.txt').file_size
# Size after compression
c_size = zip_file.getinfo('zfile/a.txt').compress_size

The namelist() method returns a list of all file and folder names in the archive. These names can be passed to getinfo() to obtain a ZipInfo object, which provides attributes such as file_size (original size) and compress_size (compressed size).

2. Extract Files from a ZIP Archive

The extractall() method extracts every file and folder in the archive to the current working directory (or to a directory you specify).

import zipfile
zip_file = zipfile.ZipFile('zfile.zip')
zip_file.extractall()
zip_file.close()

You can pass a target folder to extractall(); if the folder does not exist, it will be created automatically.

3. Create and Add to a ZIP Archive

To create a new ZIP file you open a ZipFile object in write mode by passing 'w' as the second argument.

import zipfile
zip_file = zipfile.ZipFile('new.zip', 'w')
# Add an entire directory
zip_file.write('zfile', compress_type=zipfile.ZIP_DEFLATED)
# Add a single file (example)
# zip_file.write('c.txt', compress_type=zipfile.ZIP_DEFLATED)
zip_file.close()

Opening a ZIP file in write mode overwrites any existing content. To add files to an existing archive, open it in append mode by using 'a' instead of 'w'.