PythonensurepipBootstrappingthepipinstaller

Command line interface¶

The command line interface is invoked using the interpreter's -m switch.

The simplest possible invocation is:

python-mensurepip

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-mensurepip--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, the

  pip script will be installed in addition to the two regular scripts.

Providing both of the script selection options will trigger an exception.

Module API¶

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.

注解

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.

注解

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).