update_constraints.py

#!/usr/bin/env python3
'''
update_constraints.py
Helps manage Python package version constraints by updating based on currently installed versions.

Features:

- Caution - creates a temporary file rather than overwriting your original constraints
- Preserves only packages that were in the original constraints file—doesn't add new ones
- Error handling for packages that might be missing

# Usage

```sh
chmod +x update_constraints.py  # One time, after download
pip install fire  # Required, if not already installed
./update_constraints.py path/to/your/constraints.txt
'''
import subprocess
import tempfile
import fire

def update_constraints(constraints_file):
    # Read existing constraints
    with open(constraints_file, 'r') as f:
        existing_packages = [line.split('==')[0] for line in f if '==' in line]

    # Get current versions of installed packages
    result = subprocess.run(['pip', 'freeze'], capture_output=True, text=True)
    current_versions = dict(line.split('==') for line in result.stdout.splitlines() if '==' in line)

    # Create updated constraints
    updated_constraints = []
    for package in existing_packages:
        if package in current_versions:
            updated_constraints.append(f'{package}=={current_versions[package]}')
        else:
            print(f'Warning: {package} not found in current environment')

    # Write updated constraints to a temporary file
    with tempfile.NamedTemporaryFile(mode='w', delete=False, suffix='-constraints.txt') as temp_file:
        for line in updated_constraints:
            temp_file.write(line + '\n')
        temp_file_name = temp_file.name

    print(f'Updated constraints written to {temp_file_name}')
    print('Review the file and replace your original constraints.txt if satisfied')


if __name__ == '__main__':
    fire.Fire(update_constraints)