pip install#
PyPI (and other indexes) using requirement specifiers.
VCS project urls.
Local project directories.
Local or remote source archives.
pip also supports installing from “requirements files”, which provide an easy way to specify a whole environment to be installed.
Overview#
pip install has several stages:
Identify the base requirements. The user supplied arguments are processed here.
Resolve dependencies. What will be installed is determined here.
Build wheels. All the dependencies that can be are built into wheels.
Install the packages (and uninstall anything being upgraded/replaced).
Note that pip install prefers to leave the installed version as-is unless —upgrade is specified.
Argument Handling#
When looking at the items to be installed, pip checks what type of item each is, in the following order:
Project or archive URL.
Local directory (which must contain a setup.py , or pip will report an error).
Local file (a sdist or wheel format archive, following the naming conventions for those formats).
A requirement, as specified in PEP 440.
Each item identified is added to the set of requirements to be satisfied by the install.
Working Out the Name and Version#
For each candidate item, pip needs to know the project name and version. For wheels (identified by the .whl file extension) this can be obtained from the filename, as per the Wheel spec. For local directories, or explicitly specified sdist files, the setup.py egg_info command is used to determine the project metadata. For sdists located via an index, the filename is parsed for the name and project version (this is in theory slightly less reliable than using the egg_info command, but avoids downloading and processing unnecessary numbers of files).
Any URL may use the #egg=name syntax (see VCS Support ) to explicitly state the project name.
Satisfying Requirements#
Once pip has the set of requirements to satisfy, it chooses which version of each requirement to install using the simple rule that the latest version that satisfies the given constraints will be installed (but see here for an exception regarding pre-release versions). Where more than one source of the chosen version is available, it is assumed that any source is acceptable (as otherwise the versions would differ).
Obtaining information about what was installed#
The install command has a —report option that will generate a JSON report of what pip has installed. In combination with the —dry-run and —ignore-installed it can be used to resolve a set of requirements without actually installing them.
The report can be written to a file, or to standard output (using —report — in combination with —quiet ).
The format of the JSON report is described in Installation Report .
Installation Order#
This section is only about installation order of runtime dependencies, and does not apply to build dependencies (those are specified using PEP 518).
As of v6.1.0, pip installs dependencies before their dependents, i.e. in “topological order.” This is the only commitment pip currently makes related to order. While it may be coincidentally true that pip will install things in the order of the install arguments or in the order of the items in a requirements file, this is not a promise.
In the event of a dependency cycle (aka “circular dependency”), the current implementation (which might possibly change later) has it such that the first encountered member of the cycle is installed last.
For instance, if quux depends on foo which depends on bar which depends on baz, which depends on foo:
Prior to v6.1.0, pip made no commitments about install order.
The decision to install topologically is based on the principle that installations should proceed in a way that leaves the environment usable at each step. This has two main practical benefits:
Concurrent use of the environment during the install is more likely to work.
A failed install is less likely to leave a broken environment. Although pip would like to support failure rollbacks eventually, in the mean time, this is an improvement.
Although the new install order is not intended to replace (and does not replace) the use of setup_requires to declare build dependencies, it may help certain projects install from sdist (that might previously fail) that fit the following profile:
They have build dependencies that are also declared as install dependencies using install_requires .
python setup.py egg_info works without their build dependencies being installed.
For whatever reason, they don’t or won’t declare their build dependencies using setup_requires .
Requirements File Format
This section has been moved to Requirements File Format .
This section has been moved to Requirement Specifiers .
Pre-release Versions#
Starting with v1.4, pip will only install stable versions as specified by pre-releases by default. If a version cannot be parsed as a compliant PEP 440 version then it is assumed to be a pre-release.
If a Requirement specifier includes a pre-release or development version (e.g. >=0.0.dev0 ) then pip will allow pre-release and development versions for that requirement. This does not include the != flag.
The pip install command also supports a —pre flag that enables installation of pre-releases and development releases.
This is now covered in VCS Support .
Finding Packages#
pip searches for packages on PyPI using the HTTP simple interface, which is documented here and there.
pip offers a number of package index options for modifying how packages are found.
pip looks for packages in a number of places: on PyPI (if not disabled via —no-index ), in the local filesystem, and in any additional repositories specified via —find-links or —index-url . There is no ordering in the locations that are searched. Rather they are all checked, and the “best” match for the requirements (in terms of version number — see PEP 440 for details) is selected.
SSL Certificate Verification
This is now covered in HTTPS Certificates .
This is now covered in Caching .
This is now covered in Caching .
Hash checking mode
This is now covered in Secure installs .
Local Project Installs
Build System Interface
Options#
-r , —requirement <file> #
Install from the given requirements file. This option can be used multiple times.
-c , —constraint <file> #
Constrain versions using the given constraints file. This option can be used multiple times.
Don’t install package dependencies.
Include pre-release and development versions. By default, pip only finds stable versions.
-e , —editable <path/url> #
Install a project in editable mode (i.e. setuptools “develop mode”) from a local project path or a VCS url.
Don’t actually install anything, just print what would be. Can be used in combination with —ignore-installed to ‘resolve’ the requirements.
Install packages into <dir>. By default this will not replace existing files/folders in <dir>. Use —upgrade to replace existing packages in <dir> with new versions.
Only use wheels compatible with <platform>. Defaults to the platform of the running system. Use this option multiple times to specify multiple platforms supported by the target interpreter.
The Python interpreter version to use for wheel and “Requires-Python” compatibility checks. Defaults to a version derived from the running interpreter. The version can be specified using up to three dot-separated integers (e.g. “3” for 3.0.0, “3.7” for 3.7.0, or “3.7.3”). A major-minor version can also be given as a string without dots (e.g. “37” for 3.7.0).
Only use wheels compatible with Python implementation <implementation>, e.g. ‘pp’, ‘jy’, ‘cp’, or ‘ip’. If not specified, then the current interpreter implementation is used. Use ‘py’ to force implementation-agnostic wheels.
Only use wheels compatible with Python abi <abi>, e.g. ‘pypy_41’. If not specified, then the current interpreter abi tag is used. Use this option multiple times to specify multiple abis supported by the target interpreter. Generally you will need to specify —implementation, —platform, and —python-version when using this option.
Install to the Python user install directory for your platform. Typically
/.local/, or %APPDATA%Python on Windows. (See the Python documentation for site.USER_BASE for full details.)
Install everything relative to this alternate root directory.
Installation prefix where lib, bin and other top-level folders are placed. Note that the resulting installation may contain scripts and other resources which reference the Python interpreter of pip, and not that of —prefix . See also the —python option if the intention is to install packages into another (possibly pip-free) environment.
Directory to check out editable projects into. The default in a virtualenv is “<venv path>/src”. The default for global installs is “<current dir>/src”.
Upgrade all specified packages to the newest available version. The handling of dependencies depends on the upgrade-strategy used.
Determines how dependency upgrading should be handled [default: only-if-needed]. “eager” — dependencies are upgraded regardless of whether the currently installed version satisfies the requirements of the upgraded package(s). “only-if-needed” — are upgraded only when they do not satisfy the requirements of the upgraded package(s).
Reinstall all packages even if they are already up-to-date.
Ignore the installed packages, overwriting them. This can break your system if the existing package is of a different version or was installed with a different package manager!
Ignore the Requires-Python information.
Disable isolation when building a modern source distribution. Build dependencies specified by PEP 518 must be already installed if this option is used.
Use PEP 517 for building source distributions (use —no-use-pep517 to force legacy behaviour).
Check the build dependencies when PEP517 is used.
Allow pip to modify an EXTERNALLY-MANAGED Python installation
-C , —config-settings <settings> #
Configuration settings to be passed to the PEP 517 build backend. Settings take the form KEY=VALUE. Use multiple —config-settings options to pass multiple keys to the backend.
Extra global options to be supplied to the setup.py call before the install or bdist_wheel command.
Compile Python source files to bytecode
Do not compile Python source files to bytecode
Do not warn when installing scripts outside PATH
Do not warn about broken dependencies
Do not use binary packages. Can be supplied multiple times, and each time adds to the existing value. Accepts either “:all:” to disable all binary packages, “:none:” to empty the set (notice the colons), or one or more package names with commas between them (no colons). Note that some packages are tricky to compile and may fail to install when this option is used on them.
Do not use source packages. Can be supplied multiple times, and each time adds to the existing value. Accepts either “:all:” to disable all source packages, “:none:” to empty the set, or one or more package names with commas between them. Packages without binary distributions will fail to install when this option is used on them.
Prefer older binary packages over newer source packages.
Require a hash to check each requirement against, for repeatable installs. This option is implied when any package in a requirements file has a —hash option.
Specify whether the progress bar should be used [on, off] (default: on)
Action if pip is run as a root user. By default, a warning message is shown.
Generate a JSON file describing what pip did to install the provided requirements. Can be used in combination with —dry-run and —ignore-installed to ‘resolve’ the requirements. When — is used as file name it writes to stdout. When writing to stdout, please combine with the —quiet option to avoid mixing pip logging output with JSON output.
Don’t clean up build directories.
Base URL of the Python Package Index (default https://pypi.org/simple). This should point to a repository compliant with PEP 503 (the simple repository API) or a local directory laid out in the same format.
Extra URLs of package indexes to use in addition to —index-url. Should follow the same rules as —index-url.
Ignore package index (only looking at —find-links URLs instead).
If a URL or path to an html file, then parse for links to archives such as sdist (.tar.gz) or wheel (.whl) files. If a local path or file:// URL that’s a directory, then look for archives in the directory listing. Links to VCS project URLs are not supported.
Examples#
Install SomePackage and its dependencies from PyPI using Requirement Specifiers
Installing python modules on Ubuntu
I need to install some modules for python on Ubuntu Linux 12.04. I want pygame and livewires but I’m not sure how to install them.
I have the py file for livewires, which has been specially edited (from a book I’m reading) and I want to install it but I’m not sure how to, I also want to install pygame.
5 Answers 5
There are two nice ways to install Python packages on Ubuntu (and similar Linux systems):
to use the Debian/Ubuntu package manager APT. This only works for packages that are shipped by Ubuntu, unless you change the APT configuration, and in particular there seems to be no PyGame package for Python 3.
The other option is to use PIP, the Python package manager:
to install it, then
to fetch the PyGame package from PyPI and install it for Python 3. PIP has some limitations compared to APT, but it does always fetch the latest version of a package instead of the one that the Ubuntu packagers have chosen to ship.
EDIT: to repeat what I said in the comment, pip3 isn’t in Ubuntu 12.04 yet. It can still be installed with
After this, pip is the Python 3 version of PIP, instead of pip3 . The last command is just for safety; there might be a Python 2 PIP installed as /usr/bin/pip .
Try to install pip.
You can use several approaches:
1 — Download the package by yourself. This is what I use the most. If the package follows the specifications, you should be able to install it by moving to its uncompressed folder and typing in the console:
2 — Use pip. Pip is pretty straightforward. In the console, you have to type:
You can obtain pip here https://pypi.python.org/pypi/pip and install it with method 1
One thing to note: if you aren’t using a virtualenv, you’ll have to add sudo before those commands (not recommended)
It depends on the Ubuntu version and the IDE you are using. Ubuntu 15 and older come with Python 2.7 and Ubuntu 16.04 comes with both Python 2.7 and 3.5. Now based on the IDE you are using there are several ways to do this. Let`s say you only installed Spyder from Ubuntu app store or installed Jupyter. In other words you do not have a distribution like Anaconda or Enthought which install their own Python versions. This is important to pay attention to because once you are trying to install a package/library, you need to know which Python it is being installed to.
Now assuming you just have an IDE that is connected to Ubuntu`s default Python versions, you can use the terminal to install your packages:
For python 2.7 use
For python 3.5 use
Sometimes, for reasons that I don`t know, during the package installation process, Linux blocks access to the Python so try these as well:
and for Python 3.5
These have helped me to install all the libraries that I need.
Now, if you are using a distribution like Aanaconda or Enthought, there is a good chance that the libraries that you are installing are not going to be added to the libraries that those distributions use. In order to install the libraries for these distributions, once you run the distribution, go to the ipython console and write
In case of Enthought, it has it`s own Package Manager where it has most of the libraries you need and you can install them there without using pip or anything else.
What is PIP?
PIP is a recursive acronym that stands for “PIP Installs Packages” or “Preferred Installer Program”. It’s a command-line utility that allows you to install, reinstall, or uninstall PyPI packages with a simple and straightforward command: pip.
Installing Python and PIP
Installation Guide for MacOS:
1) Go to https://www.python.org/downloads/windows/ and download Python 3.6.4 (As later versions aren’t supported at the time of writing).
2) Once you’ve downloaded it, launch it and be sure to select the custom option for install. This takes you into a configuration dialog where you can choose pip as an option to install.
3) It is recommended to select them all.
4) Check if the python version is 3.6.4.
You’re now good to go with the Python runtime and pip installer for MacOS 🙂
Installation Guide for Windows 10:
1) Go to https://www.python.org/downloads/windows/ and download Python 3.6.4 (As later versions aren’t supported at the time of writing).
2) Once you’ve downloaded it, launch it and be sure to select the custom option for install. This takes you into a configuration dialog where you can choose pip as an option to install.
3) It is recommended to select all the options while installing.
4) After the installation is complete, open the terminal at type:
5) Exit the Python Interpreter.
6) Test your pip installation.
(You’re now good to go with the Python runtime and pip installer for Windows. ��)
Managing Python Packages with PIP
Once PIP is ready, you can start installing packages from PyPI:
To install a specific version of a package instead of the latest version:
To search PyPI for a particular package:
To see details about an installed package:
To list all installed packages:
Packages for machine learning!
For Machine Learning, one requires a lot of packages. You can either install one by one when you need or install everything in advance. However, it is recommended to install them all at once.
(These are the required packages for the sample program linked below. Feel free to install based on your needs.)
Installing Statsmodel: (OPTIONAL) — If the above method didn’t work.
- You can get the latest source from our github repository. Or if you have git installed:
2. Go to the statsmodel directory.
3. If you want to keep up to date with the source on github just periodically do:
4. Once you have obtained the source, you can do (after you open terminal as administrator):
Write your first program:
You can begin testing your packages with your first machine learning program here.