Why does "pip install" inside Python raise a SyntaxError?
pip is run from the command line, not the Python interpreter. It is a program that installs modules, so you can use them from Python. Once you have installed the module, then you can open the Python shell and do
The Python shell is not a command line, it is an interactive interpreter. You type Python code into it, not commands.
Use the command line, not the Python shell (DOS, PowerShell in Windows).
C:\Program Files\Python2.7\Scripts> pip install XYZ
If you installed Python into your PATH using the latest installers, you don't need to be in that folder to run pip
Terminal in Mac or Linux
$ pip install XYZ
As @sinoroc suggested correct way of installing a package via pip is using separate process since pip may cause closing a thread or may require a restart of interpreter to load new installed package so this is the right way of using the API:
subprocess.check_call([sys.executable, '-m', 'pip', 'install', 'SomeProject']) but since Python allows to access internal API and you know what you're using the API for you may want to use internal API anyway eg. if you're building own GUI package manager with alternative resourcess like https://www.lfd.uci.edu/~gohlke/pythonlibs/
Following soulution is OUT OF DATE, instead of downvoting suggest updates. see https://github.com/pypa/pip/issues/7498 for reference.
UPDATE: Since pip version 10.x there is no more
import pipinstead use
import pip._internal as pip.
UPDATE ca. v.18
get_installed_distributions() has been removed. Instead you may use generator
freeze like this:
from pip._internal.operations.freeze import freezeprint([package for package in freeze()])# eg output ['pip==19.0.3']
If you want to use pip inside the Python interpreter, try this:
import pippackage_names=['selenium', 'requests'] #packages to installpip.main(['install'] + package_names + ['--upgrade']) # --upgrade to install or update existing packages
If you need to update every installed package, use following:
import pipfor i in pip.get_installed_distributions(): pip.main(['install', i.key, '--upgrade'])
If you want to stop installing other packages if any installation fails, use it in one single
import pippackage_names = [i.key for i in pip.get_installed_distributions()]pip.main(['install'] + package_names + ['--upgrade'])
Note: When you install from list in file with
--requirement parameter you do NOT need open() function.
pip.main(['install', '-r', 'filename'])
Warning: Some parameters as simple
--help may cause python interpreter to stop.
Curiosity: By using
pip.exe you actually use python interpreter and pip module anyway. If you unpack
pip3.exe regardless it's python 2.x or 3.x, inside is the SAME single file
# -*- coding: utf-8 -*-import reimport sysfrom pip import mainif __name__ == '__main__': sys.argv = re.sub(r'(-script\.pyw?|\.exe)?$', '', sys.argv) sys.exit(main())