A Beginner's Guide to Python's pip Package Manager

When you're writing code, you often need to rely on code that already exists and was written by somebody else. Rather than reinventing the wheel every time, developers can use such pre-written code to save time and reduce errors. Nearly every programming language provides a huge collection of such reusable party code called packages or libraries. These packages are usually focused on a single problem; for example, if you're doing data work, you might need to use a package that handles data analysis.

To make using these packages easy, programming languages typically include a program for downloading, installing, and managing such packages. These programs are called package managers. They handle the details of downloading and installing the packages, as well as installing additional packages those packages in turn need. These programs are called package managers.

In Python, the package manager is called pip (which stands for “Pip Installs Packages”) and it gets installed when you install Python. Whether you're building a simple script or a complex application, chances are you'll use pip to install at least one package to enhance your project. The good news is that pip comes pre-installed with Python, so as soon as you have Python set up on your machine, you're ready to start using it.

Here's a quick overview of what pip is, how to use it, and some tips to get the most out of it.

What is pip?

pip is the standard package management system for Python. It allows developers to easily download and install third-party libraries from the Python Package Index (PyPI) and other repositories. Although you can work with pip from the command line, you're free to browse the repository online at the Python Package Index site.

How to Use pip

Installing a Package

To install a package using pip, use the following command:

pip install <package-name>

For example, to install the popular library requests, type:

pip install requests

Installing a Specific Version

Sometimes, you need a specific version of a package. You can specify it like this:

pip install <package-name>==<version>

For example:

pip install Django==4.0.0

Viewing Installed Packages

To see a list of all the installed packages in your environment, run:

pip list

Checking Your pip Version and Upgrading

It's always a good idea to ensure you're running the latest version of pip. To check your current version, use:

pip --version

This will return output like:

pip 23.0.1 from /path/to/python/site-packages (python 3.10)

Then to upgrade pip to the latest version, use:

pip install --upgrade pip

This command ensures you're working with the most recent features and fixes.

Additional Tips

• Uninstalling Packages: To remove a package, use pip uninstall <package-name>.

• Freezing Requirements: Sometimes you want to lock in specific versions of packages in your application, just in case newer versions have differences that break your code. To create a list of installed packages for sharing or deployment, use pip freeze > requirements.txt. This will create a file called requirements, that you can include in your project.

• Installing from Requirements: To install all the packages listed in a requirements.txt file, run:

pip install -r requirements.txt

Why to include a requirements.txt file

A requirements.txt file makes it easy to share your Python project without bundling all the installed packages. Instead of including the actual packages, this file lists the names and versions of all the dependencies your project needs. When someone else wants to run your code, they can simply install the exact same packages by running pip install -r requirements.txt, ensuring their environment matches yours. This approach keeps your project lightweight and avoids the need to manually share or recreate your development setup.

Conclusion

Python's pip is an invaluable tool for managing packages and expanding the functionality of your projects. By mastering a few key commands, you'll be well-equipped to explore Python's rich ecosystem of libraries. Whether you're installing your first package or managing dependencies in a large project, pip has you covered.