pip-licenses

Warnings

• breaking `pip-licenses` versions 4.x and 5.x have dropped support for older Python versions. Specifically, 4.x discontinued support for Python 3.7, and versions 5.x require Python >=3.9 (dropping 3.8 support). Users on older Python environments should use an earlier `pip-licenses` version (e.g., `<4.0` for Python 3.7).
  Fix: Ensure your Python environment is 3.9 or newer, or install a compatible older version of `pip-licenses` (e.g., `pip install 'pip-licenses<4.0'` for Python 3.7).
• breaking When upgrading from `pip-licenses` 3.x to 4.x or later, the `PTable` dependency was removed. You must explicitly uninstall `PTable` to avoid conflicts.
  Fix: After upgrading `pip-licenses`, run `pip uninstall -y PTable`.
• breaking In version 3.5.0, the separator for displaying multiple licenses for a single package changed from a comma to a semicolon. This can affect scripts parsing the output.
  Fix: Update any parsing logic to expect semicolons as separators for multiple licenses.
• gotcha By default, `pip-licenses` ignores system-level packages (like `pip`, `setuptools`, and its own dependencies) to focus on user-installed project dependencies.
  Fix: To include system packages in the output, use the `--with-system` option: `pip-licenses --with-system`.
• gotcha `pip-licenses` is primarily a CLI tool and does not offer a direct programmatic API for import. If you are looking for a library for programmatic license detection, consider `pip-licenses-lib`, which is a separate fork providing library functionality.
  Fix: For programmatic access, use the `pip-licenses-lib` package (e.g., `pip install pip-licenses-lib`) and import `piplicenses_lib` functions.
• breaking Support for PEP 639 (SPDX License Expressions) was added, and with `pip-licenses 5.5.0`, the `--from=all` output now includes the `License-Expression` value. This change affects the structure of the output, particularly when using `--from=all`.
  Fix: Review and update any scripts that parse the `--from=all` output to account for the new `License-Expression` field.

Install

• pip install pip-licenses Install or Upgrade
• pip uninstall -y PTable Required when upgrading from pip-licenses 3.x

Quickstart

The primary usage of `pip-licenses` is through its command-line interface. After installation, simply running `pip-licenses` will display a table of all non-system Python packages and their associated licenses in your current environment. Common options include `--with-system` to include system packages, `--fail-on` to exit with an error if a specific license is detected, `--format` for different output types (e.g., json, html, markdown), and `--summary` to get a count of packages per license.

import os

# Install pip-licenses and a sample package (if not already installed)
# os.system('pip install Django pip-licenses')

# Basic usage: list all installed package licenses
print("\n--- Basic License List ---")
os.system('pip-licenses')

# Include system packages like pip and setuptools
print("\n--- With System Packages ---")
os.system('pip-licenses --with-system')

# Fail if a specific license (e.g., AGPL) is found
print("\n--- Fail on AGPL (example, might exit with error) ---")
# For demonstration, we use a common permissive license (MIT) to show failure.
# In a real scenario, you'd check for restrictive licenses like AGPL.
# This command will exit with a non-zero code if MIT is found.
# os.system('pip-licenses --fail-on "MIT License" --partial-match')

# Output in JSON format
print("\n--- Output in JSON Format (first 1000 chars) ---")
json_output = os.popen('pip-licenses --format=json').read()
print(json_output[:1000])

# Get a summary of licenses by count
print("\n--- License Summary ---")
os.system('pip-licenses --summary')