How to Check Installed Python Libraries

As a Python developer, it’s essential to keep track of the libraries and packages you’ve installed on your system. These libraries extend Python’s functionality, enabling you to perform various tasks, from data analysis and web development to machine learning and automation. In this blog post, we’ll discuss how to check the Python libraries you’ve installed, both manually and using automated tools.

Manually Checking Installed Libraries

1. Site-Packages Directory: Python libraries are typically installed in the site-packages directory of your Python installation. You can manually navigate to this directory and list the contents to see which libraries are installed. The exact location of the site-packages directory can vary depending on your operating system and Python installation.

   • On Unix-like systems, it’s often located within your Python installation directory, typically in a path like /usr/local/lib/pythonX.Y/site-packages (where X.Y is your Python version).
   • On Windows, the location can vary, but it’s often found within the Lib\site-packages directory of your Python installation folder.

   You can use the find command (on Unix-like systems) or File Explorer (on Windows) to navigate to and list the contents of the site-packages directory.

2. Package Documentation: Some libraries come with documentation that you can view locally. By navigating to the documentation folder within the library’s installation directory, you can get an overview of the library’s features and capabilities.

Using Automated Tools

The most convenient way to check installed Python libraries is to use automated tools, such as pip and conda (if you’re using Anaconda or Miniconda).

1. Using pip: pip is the package installer for Python, and it also allows you to list the installed packages. To see a list of all installed packages, open a command prompt or terminal and run the following command:

   bashpip list
   
    This command will display a list of all installed packages, along with their version numbers.
   

2. Using conda (if applicable): If you’re using Anaconda or Miniconda, you can use the conda command to list installed packages. Open a command prompt or terminal and run:

   bashconda list
   
    This command will display a list of all installed packages, including those installed via pip (if you’ve configured conda to work with pip).
   

Filtering the Output

If you want to filter the output to show only specific packages, you can use the grep command (on Unix-like systems) or the findstr command (on Windows) in conjunction with pip or conda. For example, to list only the packages that contain the word “numpy” in their name, you could run:

bashpip list | grep numpy  # Unix-like systems
pip list | findstr numpy  # Windows

(Note: The above Windows command is an example; pip list itself doesn’t directly support findstr, but you could redirect the output to a file and then use findstr on that file, or use a PowerShell command instead.)
Conclusion
Keeping track of your installed Python libraries is crucial for maintaining a healthy development environment. Whether you choose to manually navigate to the site-packages directory or use automated tools like pip and conda, there are several ways to check which libraries are installed on your system. By regularly reviewing your installed packages, you can ensure that you’re using the latest versions and that your development environment is free of unnecessary dependencies.