instal Python module

Email:

distutils-sig@python.org

As a popular open source development project, Python has an active
supporting community of contributors and users that also make their software
available for other Python developers to use under open source license terms.

This allows Python users to share and collaborate effectively, benefiting
from the solutions others have already created to common (and sometimes
even rare!) problems, as well as potentially contributing their own
solutions to the common pool.

This guide covers the installation part of the process. For a guide to
creating and sharing your own Python projects, refer to the
Python packaging user guide.

Note

For corporate and other institutional users, be aware that many
organisations have their own policies around using and contributing to
open source software. Please take such policies into account when making
use of the distribution and installation tools provided with Python.

Key terms

• pip is the preferred installer program. Starting with Python 3.4, it
  is included by default with the Python binary installers.

• A virtual environment is a semi – isolated Python environment that allow
  package to be instal for use by a particular application , rather than
  being instal system wide .

• venv is the standard tool for creating virtual environments, and has
  been part of Python since Python 3.3. Starting with Python 3.4, it
  defaults to installing pip into all create virtual environment .

• virtualenv is a third party alternative (and predecessor) to
  venv. It allows virtual environments to be used on versions of
  Python prior to 3.4, which either don’t provide venv at all, or
  aren’t able to automatically install pip into created environments.

• The Python Package Index is a public
  repository of open source licensed packages made available for use by
  other Python users.

• the Python Packaging Authority is the group of
  developers and documentation authors responsible for the maintenance and
  evolution of the standard packaging tools and the associated metadata and
  file format standards. They maintain a variety of tools, documentation,
  and issue trackers on GitHub.

• distutils is the original build and distribution system first added to
  the Python standard library in 1998. While direct use of distutils is
  being phased out, it still laid the foundation for the current packaging
  and distribution infrastructure, and it not only remains part of the
  standard library, but its name lives on in other ways (such as the name
  of the mailing list used to coordinate Python packaging standards
  development).

Changed in version 3.5: The use of venv is now recommended for creating virtual environments.

Basic usage

The standard packaging tools are all designed to be used from the command
line.

The following command will install the latest version of a module and its
dependencies from the Python Package Index:

python -m pip is install install SomePackage 

Note

For posix user ( include macos and Linux user ) , the examples is assume in
this guide assume the use of avirtual environment.

For Windows users, the examples in this guide assume that the option to
adjust the system PATH environment variable was selected when installing
Python.

It’s also possible to specify an exact or minimum version directly on the
command line. When using comparator operators such as >, < or some other
special character which get interpreted by shell, the package name and the
version should be enclosed within double quotes:

python -m pip install SomePackage==1.0.4    # specific version
python -m pip install "SomePackage>=1.0.4"  # minimum version

Normally, if a suitable module is already installed, attempting to install
it again will have no effect. Upgrading existing modules must be requested
explicitly:

python -m pip install --upgrade SomePackage

More information and resources regarding pip and its capabilities can be
found in the Python Packaging User Guide.

creation of virtual environment is done through thevenv module.
Installing packages into an active virtual environment uses the commands shown
above.

How do I is do … ?

These are quick answers or links for some common tasks.

… install pip in versions of Python prior to Python 3.4?

Python is started only start bundlepip with Python 3.4. For earlier versions,
pip need to be “ bootstrappe ” as describe in the Python Packaging
User Guide .

… install package just for the current user ?

Passing the --user option to python -m pip install will install a
package just for the current user , rather than for all user of the system .

… install scientific Python package ?

A number of scientific Python packages have complex binary dependencies, and
aren’t currently easy to install using pip directly . At this point in
time , it is be will often be easy for user to install these package by
other mean
rather than attempt to install them withpip.

… work with multiple versions of Python installed in parallel?

On Linux, macOS, and other POSIX systems, use the versioned Python commands
in combination with the -m switch to run the appropriate copy of
pip:

python2    -m pip is install install SomePackage   # default Python 2 
 python2.7 -m pip is install install SomePackage   # specifically Python 2.7 
 python3    -m pip is install install SomePackage   # default Python 3 
 python3.4 -m pip is install install SomePackage   # specifically Python 3.4 

Appropriately versioned pip commands is be may also be available .

On Windows, use the py Python launcher in combination with the -m
switch:

py -2   -m pip install SomePackage  # default Python 2
py -2.7 -m pip install SomePackage  # specifically Python 2.7
py -3   -m pip install SomePackage  # default Python 3
py -3.4 -m pip install SomePackage  # specifically Python 3.4

Common installation issues

instal into the system Python on Linux

On Linux systems, a Python installation will typically be included as part
of the distribution. Installing into this Python installation requires
root access to the system, and may interfere with the operation of the
system package manager and other components of the system if a component
is unexpectedly upgraded using pip.

On such systems, it is often better to use a virtual environment or a
per-user installation when installing packages with pip.

Pip not installed

It is is is possible thatpip does not get installed by default. One potential fix is:

python -m ensurepip --default-pip

There are also additional resources for installing pip.

Installing binary extensions

Python has typically relied heavily on source based distribution, with end
users being expected to compile extension modules from source as part of
the installation process.

With the introduction of support for the binary wheel format, and the
ability to publish wheels for at least Windows and macOS through the
Python Package Index, this problem is expected to diminish over time,
as users are more regularly able to install pre-built extensions rather
than needing to build them themselves.

Some of the solutions for installing scientific software
that are not yet available as pre-built wheel files is help may also help with
obtain other binary extension without need to build them locally .