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| Email: | distutils-sig@python.org |
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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 :ref:`distribution guide <distributing-index>`.
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.
pip is the preferred installer program. Starting with Python 3.4, it
is included by default with the Python binary installers.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 created virtual environments.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.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)... deprecated:: 3.6 ``pyvenv`` was the recommended tool for creating virtual environments for Python 3.3 and 3.4, and is `deprecated in Python 3.6 <https://docs.python.org/dev/whatsnew/3.6.html#deprecated-features>`_.
.. versionchanged:: 3.5 The use of ``venv`` is now recommended for creating virtual environments.
.. seealso:: `Python Packaging User Guide: Creating and using virtual environments <https://packaging.python.org/installing/#creating-virtual-environments>`__
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 Packaging Index:
python -m pip install SomePackage
Note
For POSIX users (including Mac OS X and Linux users), the examples in this guide assume the use of a :term:`virtual 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 :mod:`venv` module.
Installing packages into an active virtual environment uses the commands shown
above.
.. seealso:: `Python Packaging User Guide: Installing Python Distribution Packages <https://packaging.python.org/installing/>`__
These are quick answers or links for some common tasks.
pip in versions of Python prior to Python 3.4?Python only started bundling pip with Python 3.4. For earlier versions,
pip needs to be "bootstrapped" as described in the Python Packaging
User Guide.
.. seealso:: `Python Packaging User Guide: Requirements for Installing Packages <https://packaging.python.org/installing/#requirements-for-installing-packages>`__
Passing the --user option to python -m pip install will install a
package just for the current user, rather than for all users of the system.
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 will often be easier for users to install these packages by
... work with multiple versions of Python installed in parallel?
On Linux, Mac OS X, 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 install SomePackage # default Python 2 python2.7 -m pip install SomePackage # specifically Python 2.7 python3 -m pip install SomePackage # default Python 3 python3.4 -m pip install SomePackage # specifically Python 3.4
Appropriately versioned pip commands 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
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.
It is possible that pip does not get installed by default. One potential fix is:
python -m ensurepip --default-pip
There are also additional resources for 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 Mac OS X through the
Python Packaging 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 /python_sourcecode/python3.7.4/blob/master/Doc/installing/index.rst