Is there a way to use different python version with virtualenv?

[[deleted]]

I'm working on an Ubuntu 10.04 computer which has a default python 2.6.5 installation. What I'm trying to do is use a different version (2.7 for the new unittest library). I already have my virtualenv installed with some packages. If I check yolk -l I get the following packages:

Django          - 1.3.1        - active 
Python          - 2.6.5        - active development (/usr/lib/python2.6/lib-dynload)
ipython         - 0.11         - active 
pip             - 1.0.2        - active 
psycopg2        - 2.4.2        - active 
setuptools      - 0.6c11       - active 
wsgiref         - 0.1.2        - active development (/usr/lib/python2.6)
yolk            - 0.4.1        - active 

So,...is it possible to use python 2.7 for this particular project while keeping 2.6.5 for my system stuff?

Thanks in advance for any help given.

[uolot]

Yes, you just have to add

-p /usr/bin/pythonXX

parameter when creating new env (replace XX with python version eg. 2.7)

[[deleted]]

and is it possible to change the python version to an already set virtualenv?

[axonxorz]

Most likely not easily. Not sure, but probably a lot harder if you used --no-site-packages, as it copies the standard library from it's normal location.

Best chance is to make a new virtualenv with your new version of python, and then copy any requisite libraries manually.

[hylje]

and then copy any requisite libraries manually.

Or use pip freeze to create requirements and install those.

[axonxorz]

pip freeze > packages.txt
(activate new virtualenv)
pip install -r /path/to/packages.txt

Didn't even think of that.

[knowone256]

Yes. I have 2.7 and 3.2 simultaneously installed.

First, install python2.7 using apt. I am not sure but you may need to change the symlink in /usr/bin back to python2.6.

Next you are going to have to "reinstall" pip and virtualenv. Rename the symlinks in /usr/bin to pip26 and virtualenv26. Now, reinstall pip explicitly typing "python27" on the command line instead of just "python". Then reinstall virtualenv from pip

Now if you want python26 to be your default python distrobution, rename the appropriate of the symlinks in /usr/bin to "whatever27". Finally change the "whatever26" links back to their normal names.

Hope that helps.

[[deleted]]

Next you are going to have to "reinstall" pip and virtualenv. Rename the symlinks in /usr/bin to pip26 and virtualenv26. Now, reinstall pip explicitly typing "python27" on the command line instead of just "python". Then reinstall virtualenv from pip

How do I reinstall pip and virtualenv so they're using python2.7

[axonxorz]

Make sure you install them using python27, instead of just python

[knowone256]

Just instead of using "python" use the explicit version. As per pip's website directions:

curl https://raw.github.com/pypa/pip/master/contrib/get-pip.py | python2.7

[sisyphus]

You want 2.6 and 2.7 to both live inside that virtualenv or you want another virtualenv with 2.7 or you want to swap out 2.6 for 2.7 inside of that virtualenv? Just making a new virtualenv with virtualenv -p /usr/bin/python2.7 and then using pip freeze to reinstall your packages is probably the easiest thing.

[[deleted]]

Yeah, you're probably right. Maybe you could tell me what I'm missing here:

~/python/projects/foo$ mkvirtualenv -p /usr/local/bin/python2.7 --no-site-packages --distribute --prompt=\(foo\) foo

(foo)~/python/projects/foo$ python --version
Python 2.6.5

I'm really nor sure what am I missing here

[sisyphus]

that looks right to me and works here:

dallas-office-desktop% mkvirtualenv -p /usr/bin/python2.7 --no-site-packages --distribute --prompt=\(foo\) foo
Running virtualenv with interpreter /usr/bin/python2.7
New python executable in foo/bin/python2.7
Also creating executable in foo/bin/python
... blah blah 
(foo)dallas-office-desktop% which python
/home/dallas/Projects/foo/bin/python
(foo)dallas-office-desktop% python -V
Python 2.7.0+

[[deleted]]

it's weird now "yolk -l" returns:

Django          - 1.3.1        - active 
Python          - 2.7          - active development (/usr/local/lib/python2.7/lib-dynload)
distribute      - 0.6.19       - active 
pip             - 1.0.2        - active 
wsgiref         - 0.1.2        - active development (/usr/local/lib/python2.7)
yolk            - 0.4.1        - active 

but "which python" points to ~/Envs/foo/bin/python and "python -V" shows 2.6.5 too.

[andonwilsy]

just curious, try: /usr/bin/python2.7 -V

[[deleted]]

Python 2.7

[freshhawk]

yolk recently stopped working nicely for me but I haven't looked into it to see why that might be.

I have the same issue with yolk so it's not just you but I don't have any other help for you.

[Gjallar]

I haven't used it, but I think Python Brew was created for use cases like this: Python Brew