Pip is a package management system that simplifies installation and management of software packages written in Python such as those found in the Python Package Index (PyPI). Pip is not installed by default on Ubuntu 18.04, but the installation is pretty straightforward.

In this tutorial, we will show you how to install Python Pip on Ubuntu 18.04 using the apt package manager. We will also walk you through the basics of installing and managing Python packages with pip.

Prerequisites

Before continuing with this tutorial, make sure you are logged in as a user with sudo privileges.

Installing pip for Python 3

Ubuntu 18.04 ships with Python 3, as the default Python installation. Complete the following steps to install pip (pip3) for Python 3:

  1. Start by updating the package list using the following command:
    sudo apt update
  2. Use the following command to install pip for Python 3:
    sudo apt install python3-pip

    The command above will also install all the dependencies required for building Python modules.

  3. Once the installation is complete, verify the installation by checking the pip version:
    pip3 --version

    The version number may vary, but it will look something like this:

    pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6)

Installing pip for Python 2

Python 2 is not installed by default in Ubuntu 18.04. To install Python 2 and pip for Python 2, complete the following steps:

  1. Update the package index by running the following command:
    sudo apt update
  2. Install pip for Python 2 with:
    sudo apt install python-pip

    The command above will install Python2, Pip and all the dependencies required for building Python modules.

  3. Verify the installation by printing the pip version number:
    pip --version

    The version number may vary, but it will look something like this:

    pip 9.0.1 from /usr/lib/python2.7/dist-packages (python 2.7)

How to Use Pip

When installing python modules globally it is highly recommended to install distribution provided python modules using the apt package manager because they are tested to work properly on Ubuntu systems.

You should install Python modules globally using pip only if there is no package available through the package manager.

In most cases, you should use pip within a virtual environment only. Python Virtual Environments allows you to install Python modules in an isolated location for a specific project, rather than being installed globally. This way you do not have to worry about affecting other Python projects.

In this section, we show you a few useful basic pip commands. With pip, we can install packages from PyPI, version control, local projects, and from distribution files but in most cases, you will install packages from PyPI.

To view the list of all pip commands and options, type:

pip3 --help

You can get more information about a specific command using pip --help. For example to get more information about the install command, type:

pip install --help

Installing Packages with Pip

Let’s say you want to install a package called scrapy which is used for scraping and extracting data from websites.

To install the latest version of the package you need to run the following command:

pip3 install scrapy

To install a specific version of the package you would issue the following command:

pip3 install scrapy==1.5

Replace pip3 with pip if using Python 2.

Installing Packages with Pip using the Requirements Files

requirement.txt is a text file that contains a list of pip packages with their versions which are required to run a specific Python project.

Use the following command to install a list of requirements specified in a file:

pip3 install -r requirements.txt

Listing Installed Packages

To list all the installed pip packages use the command below:

pip3 list

Upgrade a Package With Pip

To upgrade an already installed package to the latest version use the following command:

pip3 install --upgrade package_name

Uninstalling Packages With Pip

To uninstall a package run:

pip3 uninstall package_name

Conclusion

In this tutorial, you have learned how to install pip on your Ubuntu machine and how to manage Python packages using pip. For more information about pip, visit the pip user guide page.

If you have any questions or feedback, feel free to comment below.