ensurepip — Bootstrapping the pip installer¶New in version 3.4.
The ensurepip package provides support for bootstrapping the pip
installer into an existing Python installation or virtual environment. This
bootstrapping approach reflects the fact that pip is an independent
project with its own release cycle, and the latest available stable version
is bundled with maintenance and feature releases of the CPython reference
interpreter.
In most cases, end users of Python shouldn’t need to invoke this module
directly (as pip should be bootstrapped by default), but it may be
needed if installing pip was skipped when installing Python (or
when creating a virtual environment) or after explicitly uninstalling
pip.
Note
This module does not access the internet. All of the components
needed to bootstrap pip are included as internal parts of the
package.
See also
The command line interface is invoked using the interpreter’s -m switch.
The simplest possible invocation is:
python -m ensurepip
This invocation will install pip if it is not already installed,
but otherwise does nothing. To ensure the installed version of pip
is at least as recent as the one bundled with ensurepip, pass the
--upgrade option:
python -m ensurepip --upgrade
By default, pip is installed into the current virtual environment
(if one is active) or into the system site packages (if there is no
active virtual environment). The installation location can be controlled
through two additional command line options:
--root <dir>: Installs pip relative to the given root directory
rather than the root of the currently active virtual environment (if any)
or the default root for the current Python installation.--user: Installs pip into the user site packages directory rather
than globally for the current Python installation (this option is not
permitted inside an active virtual environment).By default, the scripts pipX and pipX.Y will be installed (where
X.Y stands for the version of Python used to invoke ensurepip). The
scripts installed can be controlled through two additional command line
options:
--altinstall: if an alternate installation is requested, the pipX
script will not be installed.--default-pip: if a “default pip” installation is requested, thepip script will be installed in addition to the two regular scripts.Providing both of the script selection options will trigger an exception.
ensurepip exposes two functions for programmatic use:
ensurepip.version()¶Returns a string specifying the bundled version of pip that will be installed when bootstrapping an environment.
ensurepip.bootstrap(root=None, upgrade=False, user=False, altinstall=False, default_pip=False, verbosity=0)¶Bootstraps pip into the current or designated environment.
root specifies an alternative root directory to install relative to.
If root is None, then installation uses the default install location
for the current environment.
upgrade indicates whether or not to upgrade an existing installation
of an earlier version of pip to the bundled version.
user indicates whether to use the user scheme rather than installing globally.
By default, the scripts pipX and pipX.Y will be installed (where
X.Y stands for the current version of Python).
If altinstall is set, then pipX will not be installed.
If default_pip is set, then pip will be installed in addition to
the two regular scripts.
Setting both altinstall and default_pip will trigger
ValueError.
verbosity controls the level of output to sys.stdout from the
bootstrapping operation.
Note
The bootstrapping process has side effects on both sys.path and
os.environ. Invoking the command line interface in a subprocess
instead allows these side effects to be avoided.
Note
The bootstrapping process may install additional modules required by
pip, but other software should not assume those dependencies will
always be present by default (as the dependencies may be removed in a
future version of pip).