Pip packages not found - Brewed Python

问题:

Running Python 2.7.3, installed with HomeBrew, on a mac.

Installed several packages using PIP, including virtualenv. (Using virtualenv as an example, but NONE of the packages work.)

When I try to run them in terminal, it fails as follows:

$ virtualenv venv --distribute
-bash: virtualenv: command not found

Alternatively:

$ python virtualenv.py venv
/usr/local/Cellar/python/2.7.3/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python: can't open file 'virtualenv.py': [Errno 2] No such file or directory

A few other points that may help:

$ which python
/usr/local/bin/python
$ pip freeze
MySQL-python==1.2.4
...
virtualenv==1.8.4
$ echo $PATH
/usr/local/bin:/usr/local/sbin:/usr/local/mysql/bin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin
$ echo $PYTHONPATH
/usr/local/lib/python2.7/site-packages:

By default, the $PYTHONPATH was blank, I changed it in .bash_profile (didn't help). VirtualEnv does exist at that path. I also tried adding this path to the .profile $path, but that didn't help either, so I removed it.

On the HomeBrew Python page it seems to somewhat relate to this, but I am new to Python, and can't figure it out. Have spent some hours DuckDuckGo'ing with nothing gained.

Any help would be greatly appreciated.

EDIT: Updated to reflect actual usage.

回答1:

The problem was that I had not added Python to the system $PATH.

At the end of the brew install it says (viewable by typing brew info python):

Executable python scripts will be put in:  
   /usr/local/share/python
so you may want to put "/usr/local/share/python" in your PATH, too.

So, simply had to open .profile and paste it in, and all packages work.

Much thanks to MistyM on the Brew IRC channel for pointing that out!

回答2:

Download virtualenv.py if your system does not provide virtualenv command:

curl -L -o virtualenv.py https://raw.github.com/pypa/virtualenv/master/virtualenv.py

First create your virtualenv folder:

 python virtualenv.py venv # venv <-- name of the folder

You need run virtualenv's activate in shell:

 . venv/bin/activate

or

 source venv/bin/activate

This fixes PYTHONPATH and PATH. You do this once per each shell session. Then python command will magically work :)

Now run pip, packages will be installed in venv.

More info (disclaimer, I am the author) http://opensourcehacker.com/2012/09/16/recommended-way-for-sudo-free-installation-of-python-software-with-virtualenv/

回答3:

Quick work flow on creating a Virtual env

$ mkdir awesomeapp 
$cd awesomeapp
$virtualenv venv --distribute
New python executable in venv/bin/python
Installing distribute.........done.
Installing pip................done.
$source venv/bin/activate
(venv)$python

One you CD into your directory that's when you're creating your virtual venv folder to store your path.

You'll now it's active when you see the (venv)