virtualenv 不包括 pip

Question

I am trying to create a virtual environment using virtualenv on Mac OS X El Capitan. I have installed Python 2.7.11 with brew , which includes pip , wheel and setuptools by default.

Hovewer, when I try to install virtualenv following instructions in the documentation or from any other resource, I get several problems:

1. virtualenv executable is not placed in /usr/local/bin after pip makes its job, so I need to ln -s it by hand (it may indicate, that there is something wrong with installation on this step).
2. After I run virtualenv venv , it creates new environment, catches Python 2.7.11 from brew -installation, but: there is no pip inside bin folder . That means, that if I try which pip , having venv activated, it returns a global position of pip — /usr/local/bin/pip , not /path/to/venv/bin/pip .

As a consequence, installing packages inside venv uses global pip and installs them to a global sites-packages , not that inside venv , and it's quite the opposite of what environment should do.

Could you please suggest what may be wrong and how to fix it?

EDIT: The thing to mention is that I used to have other versions of Python installed on my computer, which I have recently deleted as it is described in this answer . Maybe it causes the issue, and some more thorough cleaning is needed.

Answer 1

Try removing or renaming the .pydistutils.cfg file in your home directory, eg by renaming with mv ~/.pydistutils.cfg ~/oldpydistutils.cfg

I'm putting a detailed answer here to help others, but the original credit goes to this answer . If you know what specifically in .pydistutils.cfg was causing the problem, let me know!

I was having the same issue: my virtual environments were created without a local copy of pip, although they had a local copy of python. This meant that using $ pip from within the virtual environment installed to the global package location, and was not visible to the environment's python.

How I diagnosed this on my machine:

1. I create a virtualenvironment with $ virtualenv env
2. Activated the virtual environment with $ source env/bin/activate
3. Checked python location: run (env)$ which python with output /Users/<username>/env/bin/python (as expected)
4. Checked pip location: run (env)$ which pip with output /usr/local/bin/pip (NOT expected)

To check where our packages are going, we can try to install a package in the virtual environment:

5. Try to install a package: (env)$ pip install HTTPServer which succeeds
6. Try to run the package: (env)$ python -m HTTPServer which fails with error /Users/emunsing/env/bin/python: No module named HTTPServer
7. To double-check, try to install again: (env)$ pip install HTTPServer which produces Requirement already satisfied (use --upgrade to upgrade): HTTPServer in /usr/local/lib/python2.7/site-packages

Double-checking, we see that there's no Pip in the environment's /bin folder:

$ ls env/bin activate activate.fish python python2 activate.csh activate_this.py python-config python2.7

And so while the system finds the local python version, it can't find a local pip to use and traverses the $PATH. It ended up using pip from /usr/local/bin, leaving me unable to install packages locally to the virtual environment.

Here's what I tried: - Reinstalling python brew uninstall python followed by brew upgrade and brew install python --build-from-source - Installing pip using the get-pip.py command as described in the Pip documentation

Here's what I ruled out: - I was not using sudo pip ... which caused similar problems in this other question and haven't done so at any time on this Python/pip install - My virtual environment didn't show a local installation of pip, as was the case in these similar questions: This one for Windows , This one for Mac OS X .

Ultimately, I found that eliminating the ~/.pydistutils.cfg file fixed the problem, allowing for fresh virtual environments that had their own local pip. The contents of my ~/.pydistutils.cfg file were:

[global]
verbose=1

[install]
install-scripts=$HOME/bin

[easy_install]
install-scripts=$HOME/bin

Simply renaming the ~/.pydistutils.cfg file appears to fix the problem: it seems that although this file was created by the homebrew installation, some settings in this file may be incompatible with virtualenv . While removing this file hasn't had any bad effects on my system, you may need to use the --user flag when installing packages with pip to the global environment (eg $ pip install --user HTTPServer ). Here are more details on .pydistutils.cfg if you want to work on tailoring it for your needs.

Answer 2

I had the issue when running virtualenv: "ImportError: No module named pip." My solution was to downgrade virtualenv. I had 16.2.0. pip uninstall virtualenv pip install virtualenv==15.1.0

Answer 3

1. virtualenv executable is not placed in /usr/local/bin after pip makes its job, so I need to ln -s it by hand (it may indicate, that there is something wrong with installation on this step).

Don't do that. That will only hide the bug and not solve the problem. Here's a short guide how to debug this kind of issues:

• Start with which -a python . The first path you see should be /usr/local/bin/python , if not check your PATH variable.

• Next, check which -a pip . Again the first path should be /usr/local/bin/pip . If not, run python -m ensurepip and recheck.

• Now install virtualenv using pip install virtualenv , after that check the output of which -a virtualenv . The first path should be /usr/local/bin/virtualenv , if not check the output of env |grep PYTHON for unexpected environment variables.

• Finally check the output of virtualenv --version to make sure you have the latest version.

Answer 4

Just hit same issue on Linux. Seems like there are multiple causes of this issue, but for me answer was to remove ~/.pip/ .

Details: I had this in my .pip/pip.conf for some reason I can't remember:

$ cat ~/.pip/pip.conf 
[global]
use_https = True 
index = https://pypi.python.org/pypi
prefix = /home/sam/local/

and was using local versions on Python, Pip installed at ~/local/. For some reason virtualenv installed pip must pick up prefix = /home/sam/local/ setting and pip was being installed there.

Answer 5

Try this: sudo apt install pythonV.v-distutils . In my case Vv == 3.8. This worked for me.