How to Generate an Inventory CSV of Installed pip Packages in Python

This script uses subprocess and csv to list all installed pip packages and write their names and versions into a CSV inventory file.

Easy Python 3.9+ Aug 9, 2026 Automation & scripting 14 views 0 copies

pip csv subprocess automation inventory dependencies

Python code

29 lines

Python 3.9+

import subprocess
import csv

def get_installed_packages():
    """Return a list of (name, version) tuples for installed pip packages."""
    result = subprocess.run(
        ["pip", "list", "--format=freeze"],
        capture_output=True,
        text=True,
        check=True
    )
    packages = []
    for line in result.stdout.strip().splitlines():
        if line and "==" in line:
            name, version = line.split("==", 1)
            packages.append((name, version))
    return packages

def write_inventory_csv(filename="packages_inventory.csv"):
    """Write installed packages to a CSV file with name and version columns."""
    packages = get_installed_packages()
    with open(filename, "w", newline="", encoding="utf-8") as f:
        writer = csv.writer(f)
        writer.writerow(["Package Name", "Version"])
        writer.writerows(packages)
    print(f"Wrote {len(packages)} packages to {filename}")

if __name__ == "__main__":
    write_inventory_csv()

Output

stdout

Wrote 42 packages to packages_inventory.csv

How it works

The subprocess.run call executes pip list --format=freeze and captures its output, which lists every installed package as name==version. The csv module writes these tuples into a CSV file with headers. Using check=True raises an error if pip fails, making the script fail loudly. This approach uses only the standard library, so no external dependencies are needed.

Common mistakes

Forgetting to set `newline=''` when opening the CSV file, which can cause unwanted line breaks on Windows.
Not filtering out empty lines or lines without `==`, which can cause parsing errors.
Using `pip list` without `--format=freeze` and trying to parse table output, which is fragile.

Variations

Use `pip freeze` directly instead of `pip list --format=freeze` for the same result.
Sort packages alphabetically before writing with `sorted(packages)`.

Real-world use cases

Generating a requirements manifest for reproducible deployment in CI/CD pipelines.
Automating dependency auditing by exporting installed versions for security scanning.
Creating a local backup of package versions before upgrading or migrating environments.

How to Generate an Inventory CSV of Installed pip Packages in Python

Python code

Output

How it works

Common mistakes

Variations

Real-world use cases

More from Automation & scripting

Tutorials

Quizzes

Python code

Output

How it works

Common mistakes

Variations

Real-world use cases

More from Automation & scripting

Keep learning

Tutorials

Quizzes