How can I locate a specific version of the Python interpreter?

Question

I recently updated from Python 2.7.6 to Python 2.7.9 on my Mac. My issue is that I cannot create a new virtualenv using Python 2.7.9 with the -p flag.

When I open the Python shell outside a virtual environment it is using 2.7.9:

localhost:test6 brendan$ python
Python 2.7.9 (v2.7.9:648dcafa7e5f, Dec 10 2014, 10:10:46) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

However, when I create a new virtual environment using either virtualenv or mkvirtualenv it continues to use 2.7.6.

I understand that I can use the -p flag to create a virtual environment using a specific version of Python (e.g. 3.0, 2.6, etc.), but each of these have their own executable e.g.

virtualenv -p /usr/bin/python3.0 test6

or

virtualenv -p /usr/bin/python2.6 test7

I do not seem to have a python2.7.9 executable located in /usr/bin or anywhere else. I do have a python2.7 executable, but if I specify this:

virtualenv -p /usr/bin/python2.7 test7

the resulting virtual environment still uses the 2.7.6 version of Python. I thought the installation of Python 2.7.9 should have updated the python2.7 executable in /usr/bin/?

So my question is: where is my Python 2.7.9 executable located, and how do I specify it when creating a new virtual environment?

as @thefourtheye says, try `virtualenv -p $(which python) test7` — Holloway, Mar 24 '15 at 14:10
*"I thought the installation of Python 2.7.9 should have updated the `python2.7` executable in `/usr/bin`?"* - no, see e.g. http://stackoverflow.com/q/5846167/3001761 for changing the default version. — jonrsharpe, Mar 24 '15 at 14:16

score 1 · Accepted Answer · answered Mar 24 '15 at 14:11

1

Use which to find which executable is being run from the command line, then use that to create the virtualenv.

Something like

virtualenv -p $(which python) test7

answered Mar 24 '15 at 14:11

Holloway

6,412
1
26
33

Worked perfectly. In my case it was `virtualenv -p /Library/Frameworks/Python.framework/Versions/2.7/bin/python test7` – Deepend Mar 24 '15 at 14:46

score 0 · Answer 2 · answered Mar 24 '15 at 14:25

The /usr/bin/python2.7 is simply a symbolic link to the actual python binary which could be located somewhere else. Most likely if you execute /usr/bin/python2.7 --version it will show you "Python 2.7.6".

I have not tried this on mac, but have done it on Linux, is to get a specific version of python and compile it manually in my path /users//mypython, and then modify the symbolic link in /usr/bin/python to point to my version.

How can I locate a specific version of the Python interpreter?

2 Answers2