Replace os.system('unzip file.zip') -> ZipFile.extractall()

[glenn-jocher]

This PR updates all YOLOv5 unzip ops from os.system() commands, which appear to cause Windows issues in a small number of cases, with the python built-in zipfile package, which should provide greater compatibility across operating systems.

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Refactoring of zip file extraction methods across multiple utility scripts.

📊 Key Changes

• Replaced os.system unzip calls with ZipFile.extractall method in datasets.py, downloads.py, and general.py.
• Removed command line unzip commands in favor of direct Python functions.
• Streamlined the error handling by eliminating return codes from unzip commands.
• Improved clarity in autodownload messages, explicitly stating the download location.

🎯 Purpose & Impact

• Enhanced portability and security: By using Python's ZipFile module instead of system commands, code becomes more secure and works across all operating systems without relying on external unzip utilities.
• Easier maintenance and readability: The use of built-in Python library functions ensures code is more Pythonic and easier to maintain.
• User-friendly feedback: Clearer messages about download and extraction processes improve user experience by providing direct information on where files are saved, especially during dataset autodownload.
• Streamlined error handling: Removal of system-dependent exit codes leads to more consistent and reliable error checking directly within Python's execution environment.

[glenn-jocher]

@kalenmike this will likely conflict with your open PR #4774, but also helps remove os.system() calls as you'd recommended earlier, and fixes some immediate Windows issues in #4779.

[glenn-jocher]

Before and After profiling results show slightly improved speeds :)

import os
import time
from pathlib import Path
from zipfile import ZipFile

file = Path('test/coco2017labels.zip')

t = time.time()
ZipFile(file).extractall(path=file.parent)
print(f'DONE PYTHON in {time.time() - t}s')

t = time.time()
os.system(f'unzip -qo {file} -d {file.parent}')
print(f'DONE BASH in {time.time() - t}s')

Returns

DONE PYTHON in 26.95448899269104s
DONE BASH in 31.251495122909546s