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This section covers the basics of how to install Python packages. It’s important to note that the term “package” in this context is being used to describe a bundle of software to be installed (i.e. as a synonym for a distribution). It does not to refer to the kind of package that you import in your Python source code (i.e. a container of modules). It is common in the Python community to refer to a distribution using the term “package”. Using the term “distribution” is often not preferred, because it can easily be confused with a Linux distribution, or another larger software distribution like Python itself. Contents Requirements for Installing Packages¶This section describes the steps to follow before installing other Python packages. Ensure you can run Python from the command line¶Before you go any further, make sure you have Python and that the expected version is available from your command line. You can check this by running: You should get some output like Note If you’re a newcomer and you get an error like this: >>> python3 --version Traceback (most recent call last): File "<stdin>", line 1, in <module> NameError: name 'python3' is not defined It’s because this command and other suggested commands in this tutorial are intended to be run in a shell (also called a terminal or console). See the Python for Beginners getting started tutorial for an introduction to using your operating system’s shell and interacting with Python. Note If you’re using an enhanced shell like IPython or the Jupyter
notebook, you can run system commands like those in this tutorial by
prefacing them with a
It’s recommended to write Note Due to the way most Linux distributions are handling the Python 3
migration, Linux users using the system Python without creating a virtual
environment first should replace the Ensure you can run pip from the command line¶Additionally, you’ll need to make sure you have pip available. You can check this by running: If you installed Python from source, with an installer from , or via Homebrew you should already have pip. If you’re on Linux and installed using your OS package manager, you may have to install pip separately, see Installing pip/setuptools/wheel with Linux Package Managers. If If that still doesn’t allow you to run
Ensure pip, setuptools, and wheel are up to date¶While Optionally, create a virtual environment¶See section below for details, but here’s the basic venv 3 command to use on a typical Linux system: This will create a new virtual environment in the Creating Virtual Environments¶Python “Virtual Environments” allow Python packages to be installed in an isolated location for a particular application, rather than being installed globally. If you are looking to safely install global command line tools, see Installing stand alone command line tools. Imagine you have an application that needs version 1 of LibFoo, but another application requires version 2. How can you use both these applications? If you install everything into /usr/lib/python3.6/site-packages (or whatever your platform’s standard location is), it’s easy to end up in a situation where you unintentionally upgrade an application that shouldn’t be upgraded. Or more generally, what if you want to install an application and leave it be? If an application works, any change in its libraries or the versions of those libraries can break the application. Also, what if you can’t install packages into the global site-packages directory? For instance, on a shared host. In all these cases, virtual environments can help you. They have their own installation directories and they don’t share libraries with other virtual environments. Currently, there are two common tools for creating Python virtual environments:
The basic usage is like so: Using venv: Using virtualenv: For more information, see the venv docs or the virtualenv docs. The use of source under Unix shells ensures that the virtual environment’s variables are set within the current shell, and not in a subprocess (which then disappears, having no useful effect). In both of the above cases, Windows users should _not_ use the source command, but should rather run the activate script directly from the command shell like so: <DIR>\Scripts\activate Managing multiple virtual environments directly can become tedious, so the dependency management tutorial introduces a higher level tool, Pipenv, that automatically manages a separate virtual environment for each project and application that you work on. Use pip for Installing¶pip is the recommended installer. Below, we’ll cover the most common usage scenarios. For more detail, see the pip docs, which includes a complete Reference Guide. Installing from PyPI¶The most common usage of pip is to install from the Python Package Index using a requirement specifier. Generally speaking, a requirement specifier is composed of a project name followed by an optional version specifier. PEP 440 contains a full specification of the currently supported specifiers. Below are some examples. To install the latest version of “SomeProject”: To install a specific version: To install greater than or equal to one version and less than another: To install a version that’s “compatible” with a certain version: 4 In this case, this means to install any version “==1.4.*” version that’s also “>=1.4.2”. Source Distributions vs Wheels¶pip can install from either Source Distributions (sdist) or Wheels, but if both are present on PyPI, pip will prefer a compatible wheel. You can override pip`s default behavior by e.g. using its –no-binary option. Wheels are a pre-built distribution format that provides faster installation compared to Source Distributions (sdist), especially when a project contains compiled extensions. If pip does not find a wheel to install, it will locally build a wheel and cache it for future installs, instead of rebuilding the source distribution in the future. Upgrading packages¶Upgrade an already installed Installing to the User Site¶To install packages that are isolated to the
current user, use the For more information see the User Installs section from the pip docs. Note that the If
Requirements files¶Install a list of requirements specified in a Requirements File. Installing from VCS¶Install a project from VCS in “editable” mode. For a full breakdown of the syntax, see pip’s section on VCS Support. Installing from other Indexes¶Install from an alternate index Search an additional index during install, in addition to PyPI Installing from a local src tree¶Installing from local src in Development Mode, i.e. in such a way that the project appears to be installed, but yet is still editable from the src tree. You can also install normally from src Installing from local archives¶Install a particular source archive file. Install from a local directory containing archives (and don’t check PyPI) Installing from other sources¶To install from other data sources (for example Amazon S3 storage)
you can create a helper application that presents the data
in a format compliant with the simple repository API:,
and use the ./s3helper --port=7777 python -m pip install --extra-index-url http://localhost:7777 SomeProject Installing Prereleases¶Find pre-release and development versions, in addition to stable versions. By default, pip only finds stable versions. Installing “Extras”¶Extras are optional “variants” of a package, which may include additional dependencies, and thereby enable additional functionality from the package. If you wish to install an extra for a package which you know publishes one, you can include it in the pip installation command:
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