Python’s key strength is the large number of external libraries that are available. We install a lot of packages as we continue to code in Python. Obtaining a Python list of installed modules on the system is simple.

Finding Python Modules and Packages

The two methods for getting this list that will work for you are as follows…

Without pip, use the help() function

The simplest way is to start a Python terminal and type the following command…

help(“modules”)

This will show you a list of all the modules that have been downloaded to the system. This list includes both modules and packages that are pre-loaded with Python and those that you have deliberately installed.

On my machine, this is an example of how to use the help function (Python version 2).

To get this list with the help() function, you don’t need to install any extra modules. However, this command provides no more information about the package.

• You can use the pip program to find out the version of each installed module.

Using pip to get a list of Python modules installed and their versions

You can use the pip tool to get a list of Python packages installed on your system.

For those unfamiliar with pip, it is the finest software for installing and managing other Python programs on your system. Check out the comprehensive guide to managing Python modules with pip for more information.

If you have the most recent version of Python, pip is already installed.

Run the commands below from the command prompt (not on the Python console). You’ll get a list of all the Python modules that download, along with their versions.

or pip freeze

list of pip

Here’s an example of using the pip tool to list Python packages you’ve installed on your system.

• It does not list preinstalled Python packages, unlike the help function.

All of the Python packages listed, along with their versions.

Note: Before running this command, check to see if your system has a pip installed. Python comes pre-installed with Python versions 2.7 and 3.4.

Both commands’ output lists have completely different formats. Assume you’re writing shell scripts with these commands. You can use any of the instructions for processing the output package list and retrieving information that you deem convenient.

• You can use that command if you already have parsing code for any of the output from two commands.
• Run command to get more information about a specific module.

display getopt pip

This provides the title of the module/package, its edition, the writer’s email address, the copyright, the position of the downloaded module, and the requirements.

• You can obtain the author’s email address. If you have any special questions about the Python package, you can contact the author.
• Knowing the license of a package is crucial if you’re utilizing python code for business purposes.

What is the best way to see if a Python module is downloaded?

You can use pip commands in conjunction with the grep tool to look for any specified module on your system.

grep get opt pip list

For example, you can list all installed modules that include the suffix “re” in their names.

grep re | pip list

How can you figure out how many Python modules you have installed on your system?

The wc (word count) command can use.

wc -l | pip list

Note that the grep and wc commands only operate on Linux computers.

What purpose do these commands serve?

These commands will display a list of all installed modules on your system. You can use this list to create a new environment that is identical later.

• If you’re he Python module version allows you to update the module if a new version release

What Will Happen Next?

• Check out these 39 Most Useful Python Modules, which account for 95% of all Python jobs.
• I’ll show you how to construct a Python program to get a list of Python packages and save them in a list in a future article.