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How to use virtualenv in Python project?

I'm trying to use virtualenv in my new mainly Python project. The code files are located at ~/Documents/Project, and I installed a virtual environment in there, located at ~/Documents/Project/env. I have all my packages and libraries I wanted in the env/bin folder.
The question is, how do I actually run my Python scripts, using this virtual environment? I activate it in Terminal, then open idle as a test, and try
"import django"
but it doesn't work. Basically, how can I use the libraries install in the virtual environment with my project when I run it, instead of it using the standard directories for installed Python libraries?

Check out the example below, and also the virtualenv documentation. It's actually fairly straightforward if you follow the steps:
virtualenv Project # creates a new Project dir
cd Project/bin # could just call Project/bin
. activate # should now have (Project) in the prompt name
pip install django # without this, won't be able to import django
deactivate # switch of virtual mode
I tried the above out in my Mac and worked fine. Here's a transcript for reference.
Transcript of operations
[MacMini]<Documents> :virtualenv Project
[MacMini]<Project> :cd bin/
[MacMini]<bin> :python2.7
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.
>>> import django
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named django
>>> quit()
[MacMini]<bin> :. activate
(Project)[MacMini]<bin> :pip install django
You are using pip version 6.0.6, however version 8.1.0 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Collecting django
Downloading Django-1.9.4-py2.py3-none-any.whl (6.6MB)
100% |################################| 6.6MB 1.2MB/s
Installing collected packages: django
Successfully installed django-1.9.4
(Project)[MacMini]<bin> :python
Python 2.7.10 (default, Oct 23 2015, 18:05:06)
[GCC 4.2.1 Compatible Apple LLVM 7.0.0 (clang-700.0.59.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> quit()
(Project)[MacMini]<bin> :deactivate

It's also good practice to make a requires.txt file for all your dependencies. If for example your project requires Flask and pymongo, create a file with:
Flask==<version number you want here>
pymongo==<version number you want here>
Then you can install all the necessary libraries by doing:
pip install -r requires.txt
Great if you want to share your project or don't want to remember every library you need in your virtualenv.

How to install libgit2/pygit2 into virtualenv? (Ubuntu)

I have tried dulwich, and GitPython - neither of which seem mature. Now I am trying to install libgit2/pygit2. I have successfully installed them into the host packages environment, but now I need to get them installed in the virtualenv of the app I am building.
Python 2.7.3 (default, Sep 26 2013, 20:03:06)
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pygit2
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python2.7/dist-packages/pygit2/__init__.py", line 32, in <module>
import _pygit2
ImportError: libgit2.so.0: cannot open shared object file: No such file or directory
>>>
As you can see the current issue seems to be that the globally installed libgit2.so.0 cannot be found from within the virtualenv. Fair enough, that is what virtualenv is about after all,, sandboxing. So how do I go about linking/symlinking/building a version/copy of the libgit2.so for the virtualenv ?

I found the following script in a Gist that - when run while logged into a virtualenv -- will install the current libgit2/pygit2 together there in the venv.
https://gist.github.com/olivier-m/5755638
One note of caution, update the version numbers for both libraries to the same most recent version ( 0.20.0 at this time of writing ).

Virtualenv wont work on

I have build my virtual env with this command:
virtualenv env --distribute --no-site-packages
And then I have installed several modules (django etc) into env with pip, the problem is that when I wanted to run the code on the second machine it would not work, here is what I have done:
visgean#rewitaqia:~/scripty/project_name$ source ./env/bin/activate
(env)visgean#rewitaqia:~/scripty/project_name$ python
Python 2.7.1+ (r271:86832, Sep 27 2012, 21:12:17)
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> django.__file__
'/home/visgean/scripty/project_name/env/lib/python2.7/site-packages/django/__init__.pyc'
but when I want to run it on the second machine:
(env)user#debian:~/project_name$ python
Python 2.6.6 (r266:84292, Dec 27 2010, 00:02:40)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named django
>>>
I wild error appears! The first machine is ubuntu, the second one is ubuntu. There seems to be some broken links in /home/user/project_name/env/lib/python2.7 , is that the problem? and if so, how should I prevent it/repair it?

If you are just copying the virtualenv to the second machine you may encounter some issues. From the virtualenv site:
Normally environments are tied to a specific path. That means that you
cannot move an environment around or copy it to another computer. You
can fix up an environment to make it relocatable with the command:
$ virtualenv --relocatable ENV
This will make some of the files
created by setuptools or distribute use relative paths, and will
change all the scripts to use activate_this.py instead of using the
location of the Python interpreter to select the environment.
Note: you must run this after you've installed any packages into the
environment. If you make an environment relocatable, then install a
new package, you must run virtualenv --relocatable again.

I have just noticed that I did have a wrong version of python on the second machine - debian does not have python2.7, installing 2.7 and pip for is the solution

Setting up: OS X 10.6.6 + XCode3.2 using python and cocoa

I am trying to set up working environment on
OS X 10.6.6, XCode3.2, fink using python and cocoa frameworks. I scanned few references in the net, however nothing worked for me.
I have python2.6 installed via fink together with a pyobjc-py26. When I run a python shell in the terminal I get:
localhost:PyObjCTut stymek$ which python
/usr/bin/python
localhost:PyObjCTut stymek$ python
Python 2.6.1 (r261:67515, Jun 24 2010, 21:47:49)
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import objc
>>>
Everything is OK.
When I try to build the basic code from the Xcode (e.g. 1. default Python + Cocoa template 2. example from here), the python is not able to find objc module. Why?
Traceback (most recent call last):
File "main.py", line 10, in <module>
import objc
ImportError: No module named objc

I was struggling with almost similar troubles after manually installing Python version 2.7 and 3.X...
There's no such setting in XCode - the Apple-shipped Python (v2.6) needs to be the default one.
Also, check in the /System/Library/Frameworks/Python.framework/Versions - the 'Current' symlink needs to point to the default Python v2.6

why did virtualenv not include all of the system paths?

I created a virtualenv, and while it has many system paths, it doesn't have others. Specifically, pyshared and dist-packages don't seem to be included. As a result, my system-wide MySQLdb and psycopg2 aren't available. Any ideas why?

Seems to be related to Ubuntu's messing with python and virtualenv

The only possible way that i'm aware of, is if you have created your virtualenv with the argument --no-site-packages:
from Here:
If you build with virtualenv
--no-site-packages ENV it will not inherit any packages from
/usr/lib/python2.5/site-packages (or
wherever your global site-packages
directory is). This can be used if you
don't have control over site-packages
and don't want to depend on the
packages there, or you just want more
isolation from the global system.
so Here is an example to understand more:
First i will create a virtualenv normally (without --no-site-package) and you will see that
i can always access django that is installed in my system site-packages (or dist-packages):
$ virtualenv A
New python executable in A/bin/python
Installing setuptools............done
$ source A/bin/activate
(A)$ python
Python 2.6.5 (r265:79063, Apr 16 2010, 13:57:41)
[GCC 4.4.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> django.__file__
'/usr/local/lib/python2.6/dist-packages/django/__init__.pyc'
But now i will create the virtual env using --no-site-package:
$ virtualenv B --no-site-package
New python executable in B/bin/python
Installing setuptools............done.
$ source B/bin/activate
(B)$ python
Python 2.6.5 (r265:79063, Apr 16 2010, 13:57:41)
[GCC 4.4.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named django
now you see that virtaulenv was able to access django from system dist-packages (ubuntu) in my machine.
Hope this will help :)