CODEWITHSUNDEEP
pythonpython-3.xpip
Gazzer
Gazzer

Reputation: 4646

How to install a Python package inside a virtual environment with Pip (OS X)

Edit: I'm going to close this question as the reason its happening is different from my original assumption, and it's clearer to ask the question anew:

Pip installs packages in the wrong directory with virtualenv

The accepted answer doesn't directly answer the original question, but is a very useful overview.

Based on discussion below the issue is that even after

$ source ~/PycharmProjects/Practice/venv/bin/activate 
$ pip install numpy

numpy is installed in /usr/local/lib/python2.7/site-packages
What could the reason for this be?

Original:

Using Python on OS X via Homebrew:

I've been trying much of the day to sort this out but either I get a must supply either home or prefix/exec-prefix -- not both error, or the package I try to install goes into totally the wrong place:

$ pip3 --version
pip 18.1 from /usr/local/lib/python3.7/site-packages/pip (python 3.7)
$ cd venv
$ pip3 install numpy
..... [snip with following error:]
"must supply either home or prefix/exec-prefix -- not both")

Using this hint

$ pip3 install numpy -t .

Then I get a new error, 

`Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/.../pip-install-0fvveq3v/package/'

Searching around SO gives various possibilities involving pip install setuptools. but pip install throws the above error or installs in the wrong place. i.e. the solution involves something that's causing the error in the first place.

I tried to use the Python.org installer but it didn't install pip at all. (The custom installer showed the option checked but with size zero).

Upvotes: 2

Views: 2041

Answers (1)

stop.climatechange.now
stop.climatechange.now

Reputation: 4023

An introductory overview is available in this nice tutorial. Here is a good summary with more detail. But, if you renamed or moved the virtual env dir after its creation, it could break it. Create a new one from scratch: $ cd ~/PycharmProjects; python3 -mvenv newenv ; Activate: $ source newenv/bin/activate ; Install something: $ pip install colorama (same as pip3 install only if venv activated); Check: ls ~/PycharmProjects/newenv/lib/python3*/site-packages ; Deactivate: $ deactivate

Then you could try this solution for Pycharm: how to associate a virtual environment with a python project in pycharm. PyCharm indeed comes bundled with virtualenv which could have been customized, please look into Pycharm-specific resources: creating virtual environments and installing packages in Pycharm.

If you have installed PyPI's mainstream virtualenv, by default it will create new environments with the python interpreter that virtualenv was installed with. But it's possible to specify an alternate Python Interpreter upon a new env creation: $ virtualenv -p python3.7 newenvname

Regarding the error DistutilsOptionError: must supply either home or prefix - please check this and this for solutions. Homebrew'ed mappings between python and pip are described here. The normal pip install --user is disabled in homebrewed Python, but there are workarounds. MacOS system Python doesn't provide pip, but it can installed, reinstalled or upgraded for any specific python version manually. Original non-brewed installers are also available for all Python versions: https://www.python.org/downloads/mac-osx/

By default there's no pip.conf, but it can be created by hand to customize things. All possible pip.conf locations (per-user, per-venv, and global/system-wide, and how they override each other) are listed here. If someone faces an issue, they could use pip config list command to see their active configuration, or locate pip.conf and find it.

Finally, you may want to ensure you aren't using pip against macOS' system python. Shell commands such as $ brew info python, which pip, which pip3, pip3 -V, which python3 can help you see what you actually use. Since the macOS default $PATH used to be /usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin, stock macOS binaries (including python) may take precedence over some homebrew'ed installations (including python). If so, a custom PATH could be exported via the ~/.bashrc if required.

Upvotes: 2

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