How to use the command 'pip3' (with examples)
The ‘pip3’ command is the package manager for Python. It allows users to install, upgrade, and uninstall Python packages easily. Additionally, ‘pip3’ can also save the list of installed packages to a file and install packages from a file. This article will provide examples for each of these use cases to demonstrate the functionality and versatility of the ‘pip3’ command.
Use case 1: Install a package
Code:
pip3 install package
Motivation: This use case is useful when you want to install a specific Python package. Installing packages with ‘pip3’ allows you to quickly add new functionalities or libraries to your Python projects.
Explanation:
pip3: The command to invoke the package manager.install: The sub-command to indicate that we want to install a package.package: The name of the package that you want to install.
Example output:
Collecting package
Downloading package-1.0.tar.gz (10 kB)
Building wheels for collected packages: package
Building wheel for package (setup.py): started
Building wheel for package (setup.py): finished with status 'done'
Created wheel for package: ...
Successfully built package
Installing collected packages: package
Successfully installed package-1.0
Use case 2: Install a specific version of a package
Code:
pip3 install package==version
Motivation: Sometimes it is necessary to install a particular version of a package. This use case allows you to specify the exact version of the package you want to install.
Explanation:
pip3: The command to invoke the package manager.install: The sub-command to indicate that we want to install a package.package==version: The name of the package and the desired version separated by “==”. This specifies the specific version of the package to be installed.
Example output:
Collecting package==version
Downloading package-1.0.tar.gz (10 kB)
Building wheels for collected packages: package
Building wheel for package (setup.py): started
Building wheel for package (setup.py): finished with status 'done'
Created wheel for package: ...
Successfully built package
Installing collected packages: package
Successfully installed package-1.0
Use case 3: Upgrade a package
Code:
pip3 install --upgrade package
Motivation: When a newer version of a package becomes available, you may want to upgrade the installed version to take advantage of bug fixes, improvements, or new features. This use case allows you to upgrade a specific package to the latest version.
Explanation:
pip3: The command to invoke the package manager.install: The sub-command to indicate that we want to install a package.--upgrade: This argument enables the upgrade functionality of ‘pip3’.package: The name of the package that you want to upgrade.
Example output:
Collecting package
Downloading package-2.0.tar.gz (10 kB)
Building wheels for collected packages: package
Building wheel for package (setup.py): started
Building wheel for package (setup.py): finished with status 'done'
Created wheel for package: ...
Successfully built package
Installing collected packages: package
Successfully installed package-2.0
Use case 4: Uninstall a package
Code:
pip3 uninstall package
Motivation: In some cases, you no longer need a specific package and want to remove it from your Python environment. This use case allows you to uninstall a package.
Explanation:
pip3: The command to invoke the package manager.uninstall: The sub-command to indicate that we want to uninstall a package.package: The name of the package that you want to uninstall.
Example output:
Uninstalling package-1.0:
Would remove:
...
Proceed (y/n)? y
Successfully uninstalled package-1.0
Use case 5: Save the list of installed packages to a file
Code:
pip3 freeze > requirements.txt
Motivation: Keeping track of the installed packages in your Python projects can be helpful, especially when working on a collaborative project or when migrating to a new environment. This use case allows you to save the list of installed packages to a file.
Explanation:
pip3: The command to invoke the package manager.freeze: The sub-command that lists all installed packages.>: Redirects the output of the ‘pip3 freeze’ command to a file.requirements.txt: The name of the file where the list of packages will be saved.
Example output (content of requirements.txt):
package==1.0
Use case 6: Install packages from a file
Code:
pip3 install --requirement requirements.txt
Motivation: Instead of manually typing and installing each package, you can use this use case to install multiple packages specified in a requirements file. This is particularly useful when you want to ensure a consistent development environment across different machines or when distributing your project to others.
Explanation:
pip3: The command to invoke the package manager.install: The sub-command to indicate that we want to install a package.--requirement: This argument specifies a requirements file from where all the packages will be installed.requirements.txt: The name of the requirements file.
Example output:
Collecting package==1.0
Downloading package-1.0.tar.gz (10 kB)
Building wheels for collected packages: package
Building wheel for package (setup.py): started
Building wheel for package (setup.py): finished with status 'done'
Created wheel for package: ...
Successfully built package
Installing collected packages: package
Successfully installed package-1.0
Use case 7: Show installed package info
Code:
pip3 show package
Motivation: Sometimes it is necessary to know detailed information about a particular installed package, such as its version, location, or installation date. This use case allows you to retrieve such information.
Explanation:
pip3: The command to invoke the package manager.show: The sub-command to indicate that we want to show information about a package.package: The name of the package that you want to get information about.
Example output:
Name: package
Version: 1.0
Summary: Example package
Home-page: https://example.com/package
Author: Jane Doe
Author-email: jane@example.com
License: MIT
Location: /path/to/package
Requires:
Required-by: another_package
Conclusion:
The ‘pip3’ command is an essential tool for managing Python packages. Whether you need to install or uninstall packages, upgrade them to the latest version, or save and install them from a requirements file, ‘pip3’ provides a simple and powerful solution for all your package management needs. Understanding and utilizing these different use cases will help you efficiently work with Python packages and streamline your development process.
