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 as a synonym for a distribution (i.e. a bundle of software to be installed), 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.
- Requirements for Installing Packages
- Creating Virtual Environments
- Use pip for Installing
- Installing from PyPI
- Source Distributions vs Wheels
- Upgrading packages
- Installing to the User Site
- Requirements files
- Installing from VCS
- Installing from other Indexes
- Installing from a local src tree
- Installing from local archives
- Installing Prereleases
- Installing Setuptools “Extras”
This section describes the steps to follow before installing other Python packages.
On Linux or OS X:
pip install -U pip setuptools
python -m pip install -U pip setuptools
If you’re using a Python install on Linux that’s managed by the system package manager (e.g “yum”, “apt-get” etc...), and you want to use the system package manager to install or upgrade pip, then see Installing pip/setuptools/wheel with Linux Package Managers
Be cautious if you’re using a Python install that’s managed by your operating system or another package manager. get-pip.py does not coordinate with those tools, and may leave your system in an inconsistent state.
Python “Virtual Environments” allow Python packages to be installed in an isolated location for a particular application, rather than being installed globally.
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/python2.7/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 viable tools for creating Python virtual environments:
- venv is available by default in Python 3.3 and later, and installs pip and setuptools into created virtual environments in Python 3.4 and later.
- virtualenv needs to be installed separately, but supports Python 2.6+ and Python 3.3+, and pip, setuptools and wheel are always installed into created virtual environments by default (regardless of Python version).
The basic usage is like so:
virtualenv <DIR> source <DIR>/bin/activate
python3 -m venv <DIR> source <DIR>/bin/activate
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”:
pip install 'SomeProject'
To install a specific version:
pip install 'SomeProject==1.4'
To install greater than or equal to one version and less than another:
pip install 'SomeProject>=1,<2'
pip install 'SomeProject~=1.4.2'
In this case, this means to install any version “==1.4.*” version that’s also “>=1.4.2”.
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.
Upgrade an already installed SomeProject to the latest from PyPI.
pip install --upgrade SomeProject
To install packages that are isolated to the
current user, use the
pip install --user SomeProject
For more information see the User Installs section from the pip docs.
Install a list of requirements specified in a Requirements File.
pip install -r requirements.txt
Install a project from VCS in “editable” mode. For a full breakdown of the syntax, see pip’s section on VCS Support.
pip install -e git+https://git.repo/some_pkg.git#egg=SomeProject # from git pip install -e hg+https://hg.repo/some_pkg.git#egg=SomeProject # from mercurial pip install -e svn+svn://svn.repo/some_pkg/trunk/#egg=SomeProject # from svn pip install -e git+https://git.repo/some_pkg.git@feature#egg=SomeProject # from a branch
Install from an alternate index
pip install --index-url http://my.package.repo/simple/ SomeProject
Search an additional index during install, in addition to PyPI
pip install --extra-index-url http://my.package.repo/simple SomeProject
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.
pip install -e <path>
You can also install normally from src
pip install <path>
Install a particular source archive file.
pip install ./downloads/SomeProject-1.0.4.tar.gz
Install from a local directory containing archives (and don’t check PyPI)
pip install --no-index --find-links=file:///local/dir/ SomeProject pip install --no-index --find-links=/local/dir/ SomeProject pip install --no-index --find-links=relative/dir/ SomeProject
Find pre-release and development versions, in addition to stable versions. By default, pip only finds stable versions.
pip install --pre SomeProject
Install setuptools extras.
$ pip install SomePackage[PDF] $ pip install SomePackage[PDF]==3.0 $ pip install -e .[PDF]==3.0 # editable project in current directory
|||“Secure” in this context means using a modern browser or a tool like curl that verifies SSL certificates when downloading from https URLs.|
|||Depending on your platform, this may require root or Administrator access. pip is currently considering changing this by making user installs the default behavior.|
|||Beginning with Python 3.4, |
|||The compatible release specifier was accepted in PEP 440 and support was released in setuptools v8.0 and pip v6.0|