How to use Python 3 (3.5) as the default interpreter in my virtual environment?

Question

I ran into problems when I installed Python 3.5 on Mac. I wanted to use Python 3.5 as the interpreter when I ran my Django development server. I got this issue when I tried it (I know I must install a virtualenv, read below):

$ python3 manage.py runserver
Traceback (most recent call last):
  File "manage.py", line 7, in <module>
    from mezzanine.utils.conf import real_project_name
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/Mezzanine-4.0.1-py3.5.egg/mezzanine/utils/conf.py", line 7, in <module>
    from django.conf import global_settings as defaults
ImportError: No module named 'django'

The first was when I tried installing pip packages it installed by default on the Python 2.7 in my virtual environment:

pip install django==1.9rc2
Collecting django==1.9rc2
  Downloading Django-1.9rc2-py2.py3-none-any.whl (6.4MB)
    100% |████████████████████████████████| 6.4MB 66kB/s 
Installing collected packages: django
Successfully installed django-1.9rc2

I use Django so I tried also install a virtual environment for the first time. First I tried it with pip, but that didn't work.

So how do I setup so that my Python3.5 is the default usage when using Python interpreter and in my virtual environment? I can't figure this out or I have done something wrong in my process.

Edit:

Thanks for the answer and comment. I tried with the both solutions and the same error persisted. See output below:

$ virtualenv -p /Library/Frameworks/Python.framework/Versions/3.5/bin/python3.5 Django/
Running virtualenv with interpreter /Library/Frameworks/Python.framework/Versions/3.5/bin/python3.5
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/virtualenv.py", line 14, in <module>
    import shutil
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/shutil.py", line 10, in <module>
    import fnmatch
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/fnmatch.py", line 15, in <module>
    import functools
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/functools.py", line 21, in <module>
    from collections import namedtuple
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/collections/__init__.py", line 16, in <module>
    from reprlib import recursive_repr as _recursive_repr
  File "/Library/Python/2.7/site-packages/reprlib/__init__.py", line 7, in <module>
    raise ImportError('This package should not be accessible on Python 3. '
ImportError: This package should not be accessible on Python 3. Either you are trying to run from the python-future src folder or your installation of python-future is corrupted.

My virtualenv version: 13.1.2

try this when creating a new virtualenv `$ virtualenv -p /usr/bin/python3.5 ` taken from http://stackoverflow.com/questions/1534210/use-different-python-version-with-virtualenv — qasimalbaqali, Dec 01 '15 at 13:20
@qasimalbaqali: I tried with that, check the output above in my question. — lol5433, Dec 01 '15 at 13:32
Have you actually activate your virtualenv? Also what version of virtualenv are you using? — Padraic Cunningham, Dec 01 '15 at 13:34
@PadraicCunningham he is trying to create a virtualenv so he cannot actually activate it before creating a python 3.5 virtualenv. — qasimalbaqali, Dec 01 '15 at 13:36
@PadraicCunningham: Yes, It worked for Python 2.7. But then I tried again because I wanted Python 3.5 instead and now I can't even create a virtual environment. — lol5433, Dec 01 '15 at 13:36
Yep, defo downgrade your virtualenv as per the link in my answer. `pip install virtualenv==12.0.2` — Padraic Cunningham, Dec 01 '15 at 13:46

score 3 · Accepted Answer · answered Dec 01 '15 at 13:41

3

Your error is related to a known virtualenv bug regarding python-future and mixing up the 2.7 and 3.x module paths, the solution is to downgrade virtualenv to a version < 12.04, 12.0.2 is suggested in the link.

answered Dec 01 '15 at 13:41

Padraic Cunningham

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Allen Fernandes · Answer 2 · 2015-12-01T13:29:09.917

2

Firstly, If you are going to use multiple versions of python,then you must use Virtual Env.Also then Create your virtualenv using the following command so that it uses python 3.5 as default environment :

          virtualenv -p python3 envname

and then install django in the virtualenv.after activating your virtualenv

edited Dec 01 '15 at 13:29

answered Dec 01 '15 at 13:23

Allen Fernandes

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How to use Python 3 (3.5) as the default interpreter in my virtual environment?

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