File Compression and Decompression in Python: zipfile and gzip

File compression and decompression are essential tasks in managing data efficiently. In Python, there are built-in modules that facilitate these operations, notably `zipfile` for handling ZIP archives and `gzip` for handling Gzip archives. These tools are instrumental in reducing the size of files and directories, enabling faster data transfer, and saving storage space. This comprehensive guide will dive deeply into using `zipfile` and `gzip` for file compression and decompression in Python.

Using the ZipFile Module

The `zipfile` module in Python provides tools to create, read, write, append, and list a ZIP file. ZIP files are common archive formats that support lossless data compression.

Creating a ZIP Archive

To create a ZIP archive using the `zipfile` module, you need to initialize a `ZipFile` object in write mode and add files to it using the `write()` method. Here’s a step-by-step example:


import zipfile

# Files to be added to the archive
files_to_zip = ['example1.txt', 'example2.txt']

# Creating a new ZIP file
with zipfile.ZipFile('archive.zip', 'w') as zipf:
    for file in files_to_zip:
        zipf.write(file)

print("Files zipped successfully!")

Files zipped successfully!

In this code snippet, we create a ZIP archive named `archive.zip` and add `example1.txt` and `example2.txt` to it. The `with` statement is used for file handling to ensure files are closed properly.

Reading a ZIP Archive

Reading the contents of a ZIP file is straightforward. You can list all files contained in a ZIP archive and extract them as needed:


# Open the ZIP file in read mode
with zipfile.ZipFile('archive.zip', 'r') as zipf:
    # List all contents
    print("Contents of ZIP archive:")
    zipf.printdir()

Contents of ZIP archive:
File Name        Modified             Size
example1.txt     <datetime>           <size>
example2.txt     <datetime>           <size>

Here, the `ZipFile.printdir()` method is used to display the contents of the ZIP archive, providing file names along with their details.

Extracting Files from a ZIP Archive

To extract files, you can use the `extractall()` or `extract()` method. Here is how you can extract all files from a ZIP archive:


# Extract all files to the current directory
with zipfile.ZipFile('archive.zip', 'r') as zipf:
    zipf.extractall()

print("Files extracted successfully!")

Files extracted successfully!

The `extractall()` method extracts all files from the archive into the current directory. Alternatively, you can specify a path to extract files to a different location.

Password Protection

The `zipfile` module also supports password protection. You can encrypt your ZIP file using the `pwd` parameter with the `extract()` method.

Using the Gzip Module

The `gzip` module in Python is used to work with files in the Gzip format, which is commonly used in Unix systems. Unlike `zipfile`, `gzip` is typically used for compressing single files.

Compressing a File with Gzip

Compressing a file using Gzip is simple. Use the `gzip.open()` function to compress the contents of a file:


import gzip
import shutil

# File paths
original_file = 'example.txt'
gzipped_file = 'example.txt.gz'

# Compress the file
with open(original_file, 'rb') as f_in:
    with gzip.open(gzipped_file, 'wb') as f_out:
        shutil.copyfileobj(f_in, f_out)

print("File compressed successfully!")

File compressed successfully!

In this example, we use the `shutil.copyfileobj()` method to copy the contents from the original file to the gzip-compressed file.

Decompressing a Gzip File

To decompress a Gzip file, you reverse the process using `gzip.open()`:


# Decompress the file
with gzip.open(gzipped_file, 'rb') as f_in:
    with open('example_decompressed.txt', 'wb') as f_out:
        shutil.copyfileobj(f_in, f_out)

print("File decompressed successfully!")

File decompressed successfully!

This snippet decompresses `example.txt.gz` back to its original form as `example_decompressed.txt`.

File Modes in Gzip

The `gzip` module supports various file modes, such as read (`’rb’`), write (`’wb’`), and append (`’ab’`). It is crucial to choose the correct mode when working with Gzip files to avoid errors.

Conclusion

Python’s `zipfile` and `gzip` modules offer robust tools for file compression and decompression. Whether you need to handle batch file operations with `zipfile` or compress individual files with `gzip`, these modules provide the flexibility and efficiency required. By understanding and utilizing these tools, you can streamline data storage and transfer processes, making Python a reliable choice for managing compressed files.

About Editorial Team

Our Editorial Team is made up of tech enthusiasts who are highly skilled in Apache Spark, PySpark, and Machine Learning. They are also proficient in Python, Pandas, R, Hive, PostgreSQL, Snowflake, and Databricks. They aren't just experts; they are passionate teachers. They are dedicated to making complex data concepts easy to understand through engaging and simple tutorials with examples.

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