How to List All Available Versions of a Python Package

Knowing the available versions of a Python package is essential for managing dependencies, troubleshooting compatibility issues, and choosing the right version for your project.

This guide explains how to list all available versions of a Python package using pip, querying PyPI directly, and using a programmatic approach with the requests library.

Using pip index versions (Recommended - pip 21.1+)

Starting with pip version 21.1, the pip index versions command provides a direct and reliable way to list available package versions without attempting to install anything. This is now the recommended method.

pip index versions <package_name>

pip index versions requests

• Replace <package_name> with the actual name of the package (e.g., requests, numpy, django).
• The output lists available versions from newest to oldest, along with the package name and the supported Python versions.
• This method is fast, efficient, and doesn't involve any "tricks" or workarounds.

If the command above doesn't work for you, check your pip version:

pip --version

If it's below 21.1 update it using:

pip install --upgrade pip
python -m pip install --upgrade pip
python3 -m pip install --upgrade pip
py -m pip install --upgrade pip # Windows

Using pip install == (Works with older pip versions)

Before pip index versions was available, a common technique was to use pip install with an invalid version specifier (e.g., ==). This causes pip to list available versions in the error message.

pip install <package_name>==

pip install requests==

This method still works with current versions of pip, but the output format has changed over time, and can be less clear.

Example Output (older pip versions):

ERROR: Could not find a version that satisfies the requirement requests== (from versions: 0.2.0, 0.2.1, 0.2.2, ..., 2.28.1, 2.29.0, 2.31.0)
ERROR: No matching distribution found for requests==

Example Output (newer pip versions):

ERROR: Could not find a version that satisfies the requirement requests== (from versions: none)
ERROR: No matching distribution found for requests==

• It is recommended to use pip index versions if your version of pip is newer than 21.1, as the result is more accurate, and the command is more straightforward.
• If your version is pip install --use-deprecated=legacy-resolver requests== can be used, but is not recommended.

Querying the PyPI JSON API

For programmatic access to package versions (e.g., within a Python script), you can query the PyPI JSON API:

import requests

def list_versions(package_name):
    url = f"https://pypi.org/pypi/{package_name}/json"
    try:
        response = requests.get(url, timeout=10)
        response.raise_for_status()  # Raise HTTPError for bad responses (4xx or 5xx)
        data = response.json()
        versions = sorted(data['releases'].keys(), reverse=True) # Sort from newest to oldest
        return versions
    except requests.exceptions.RequestException as e:
        print(f"Error fetching data from PyPI: {e}")
        return [] # Return empty list

versions = list_versions('requests')
if versions:
  print(versions) # For example: ['2.31.0', '2.30.0', '2.29.0', '2.28.2', '2.28.1', '2.28.0', ..., '0.2.0']  
else:
   print("No versions found or error occurred.")

• requests.get(url, timeout=10): Fetches the JSON data from PyPI. The timeout is essential to prevent your script from hanging indefinitely if PyPI is slow or unavailable.
• response.raise_for_status(): Raises an exception if the HTTP request returns an error status code (4xx or 5xx). This is crucial for robust error handling.
• data['releases'].keys(): The JSON data has a releases key, which is a dictionary where the keys are the version strings.
• sorted(..., reverse=True): Sorts the versions in descending order (newest first). This is generally the most useful order. We use the default string sorting, which works correctly for most well-behaved version strings.
• Error Handling: If the request to the URL fails, it is handled in the except block and returns an empty list.