Handling ZIP Files in Python - Rishan Solutions

Python provides built-in support for handling ZIP files using the zipfile module. ZIP files allow multiple files to be compressed into a single archive, reducing file size and simplifying file transfers.

Why Use ZIP Files?

Reduces file size (compression).
Groups multiple files together for easy sharing.
Supports password protection (with third-party libraries).
Extracts files without modifying the originals.

1. Importing the `zipfile` Module

To work with ZIP files, first import the zipfile module:

import zipfile

2. Creating a ZIP File (`write` mode)

Use zipfile.ZipFile() in write mode ("w") to create a ZIP file and add files to it.

Example: Creating a ZIP File

import zipfile

# Create a ZIP file and add files
with zipfile.ZipFile("my_archive.zip", "w") as zipf:
    zipf.write("file1.txt")  # Add file1.txt to the ZIP
    zipf.write("file2.txt")  # Add file2.txt to the ZIP

print("ZIP file created successfully!")

The "w" mode overwrites an existing ZIP file. Use "a" to append.

3. Adding Files to an Existing ZIP (`append` mode)

with zipfile.ZipFile("my_archive.zip", "a") as zipf:
    zipf.write("new_file.txt")  # Add new_file.txt

print("File added to ZIP successfully!")

Use "a" mode to append files without overwriting the ZIP file.

4. Creating a ZIP File with Compression

To reduce file size, use ZIP_DEFLATED compression.

with zipfile.ZipFile("compressed.zip", "w", zipfile.ZIP_DEFLATED) as zipf:
    zipf.write("file1.txt")
    zipf.write("file2.txt")

print("Compressed ZIP file created!")

Compression reduces file size but takes extra processing time.

5. Extracting Files from a ZIP

Extract a Single File

with zipfile.ZipFile("my_archive.zip", "r") as zipf:
    zipf.extract("file1.txt", "output_folder")  # Extract to output_folder

print("File extracted successfully!")

Extract All Files

with zipfile.ZipFile("my_archive.zip", "r") as zipf:
    zipf.extractall("output_folder")  # Extract all files to output_folder

print("All files extracted successfully!")

Always specify an output folder to avoid cluttering the working directory.

6. Listing Files Inside a ZIP

with zipfile.ZipFile("my_archive.zip", "r") as zipf:
    print(zipf.namelist())  # List of files inside ZIP

Use namelist() to get a list of archived files.

7. Checking File Information Inside a ZIP

with zipfile.ZipFile("my_archive.zip", "r") as zipf:
    for file_info in zipf.infolist():
        print(f"Filename: {file_info.filename}, Size: {file_info.file_size} bytes")

Use infolist() to get details like file size and modification date.

8. Checking if a File Exists in a ZIP

with zipfile.ZipFile("my_archive.zip", "r") as zipf:
    if "file1.txt" in zipf.namelist():
        print("file1.txt exists in the ZIP!")

Useful for verifying the presence of specific files.

9. Deleting a File from a ZIP (Workaround)

The zipfile module does not support direct deletion of files. To remove a file, create a new ZIP without the unwanted file.

import zipfile

# Create a new ZIP without "file1.txt"
with zipfile.ZipFile("my_archive.zip", "r") as zipf:
    files = [f for f in zipf.namelist() if f != "file1.txt"]

with zipfile.ZipFile("new_archive.zip", "w") as new_zip:
    for file in files:
        new_zip.write(file)

print("File removed from ZIP!")

Creates a new ZIP without the unwanted file.

10. Password-Protecting a ZIP File (Using `pyzipper`)

The zipfile module does not support password-protected ZIPs, but the pyzipper library does.

import pyzipper

with pyzipper.AESZipFile("secure.zip", "w", compression=pyzipper.ZIP_DEFLATED, encryption=pyzipper.WZ_AES) as zipf:
    zipf.setpassword(b"mypassword")  # Set password (must be bytes)
    zipf.write("file1.txt")

print("Password-protected ZIP created!")

Install pyzipper:

pip install pyzipper

11. Extracting a Password-Protected ZIP (`pyzipper`)

import pyzipper

with pyzipper.AESZipFile("secure.zip", "r") as zipf:
    zipf.setpassword(b"mypassword")  # Provide the password
    zipf.extractall("output_folder")

print("Password-protected ZIP extracted!")

Password must be provided as bytes (b"mypassword").

12. Handling ZIP File Errors (`try-except`)

To avoid crashes, use exception handling.

import zipfile

try:
    with zipfile.ZipFile("my_archive.zip", "r") as zipf:
        zipf.extractall("output_folder")
except FileNotFoundError:
    print("Error: ZIP file not found!")
except zipfile.BadZipFile:
    print("Error: Invalid ZIP file!")

Common Errors:

FileNotFoundError – ZIP file is missing.
zipfile.BadZipFile – Corrupt or invalid ZIP file.

13. Summary Table

Operation	Method	Example
Create a ZIP file	`zipfile.ZipFile("file.zip", "w")`	`zipf.write("file.txt")`
Append to ZIP file	`zipfile.ZipFile("file.zip", "a")`	`zipf.write("new_file.txt")`
Extract a single file	`extract("file.txt")`	`zipf.extract("file.txt", "folder")`
Extract all files	`extractall("folder")`	`zipf.extractall("folder")`
List ZIP contents	`namelist()`	`zipf.namelist()`
Check file info	`infolist()`	`zipf.infolist()`
Check if file exists	`"file.txt" in zipf.namelist()`	`if "file.txt" in zipf.namelist():`
Delete a file	Create new ZIP without file	Workaround method
Password protect ZIP	`pyzipper.AESZipFile()`	`zipf.setpassword(b"mypassword")`
Handle errors	`try-except`	`except zipfile.BadZipFile:`

1. Importing the zipfile Module

2. Creating a ZIP File (write mode)