ImportError: No module named rest_framework on running collectstatic - django

Question

I found many questions with the same error, but none were addressing the actual cause of my problem so I am posting this. I am facing the issue in my (digital ocean) Linux production server.
I have python 3.5.2 in virtualenv, and python2.7.12 in the machine.
I have installed djangorestframework in virtualenv using command pip install djangorestframework
But did not install it in the actual machine (on 2.7)
python3 in the venv is working and importing rest_framework fine:
(venv) myname#server:/www/site$ python
Python 3.5.2 (default, Nov 17 2016, 17:05:23)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import rest_framework
>>> exit()
python2 in the machine is working and not importing rest_framework because its not installed.
myname#server:/www/site$ python
Python 2.7.12 (default, Nov 19 2016, 06:48:10)
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import rest_framework
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named rest_framework
>>> exit()
On running collectstatic command inside virtualenv I am getting the following error. It seems to be looking for the package in python2.7 and not inside virtualenv.
(venv) myname#server:/www/site$ sudo python manage.py collectstatic
Traceback (most recent call last):
File "manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
utility.execute()
File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 341, in execute
django.setup()
File "/usr/local/lib/python2.7/dist-packages/django/__init__.py", line 27, in setup
apps.populate(settings.INSTALLED_APPS)
File "/usr/local/lib/python2.7/dist-packages/django/apps/registry.py", line 85, in populate
app_config = AppConfig.create(entry)
File "/usr/local/lib/python2.7/dist-packages/django/apps/config.py", line 90, in create
module = import_module(entry)
File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
__import__(name)
ImportError: No module named rest_framework
My questing is that, Is it necessary for the package to be present in the server machine outside venv also?
If so, why? and Should I install rest_framework in the server on py2.7? If I do so, could it possibly break something?

Answer 1

(venv) myname#server:/www/site$ sudo python manage.py collectstatic
The issue is with the use of sudo here. It discards the environment to use the target account's one therefore discarding your virtual env.
If you want to keep it, you should likely use the -E flag to preserve the environment:
(venv) myname#server:/www/site$ sudo -E python manage.py collectstatic
you could also call the virtual env's python directly as well which would free you from setting up the visual env beforehand:
(venv) myname#server:/www/site$ which python
<path-to-python>
(venv) myname#server:/www/site$ sudo <path-to-python> manage.py collectstatic