Install python-numpy in the Virtualenv environment
numpy, python, ubuntu-12.04, virtualenv
Solution
`apt-get` will still install modules globally, even when you're in your new `virtualenv`.
You should either use `pip install numpy` from within your virtual environment (easiest way), or else compile and install `numpy` from source using the `setup.py` file in the root of the source directory (slightly harder way, see here).
I'd also thoroughly recommend you take a look at `virtualenvwrapper`, which makes managing virtual environments much friendlier.
Edit:
You should not be using `sudo`, either to create your virtual environment or to install things within it - it's a directory in your home folder, you don't need elevated permissions to make changes to it. If you use `sudo`, `pip` will make changes to your global site packages, not to your virtual environment, hence why you weren't able to install `numpy` locally.
Another thing to consider is that by default, new `virtualenvs` will inherit from the global `site-packages` - i.e. if Python can't find a module locally within your `virtualenv`, Python will also look in your global site packages *. In your case, since you'd already installed `numpy` globally (using `apt-get`), when you then try to `pip install numpy` in your virtual environment, `pip` sees that `numpy` is already in your Python path and doesn't install it locally.
You could:
Pass the `--no-site-packages` option when you create your `virtualenv`. This prevents the new `virtualenv` from inheriting from the global site packages, so everything must be installed locally.
Force `pip` to install/upgrade `numpy` locally, e.g. using `pip install -U --force numpy`
* As of v1.7, the default behaviour of `virtualenv` is to not include the global `site-packages` directory. You can override this by passing the `--system-site-packages` flag when creating a new virtual environment.
Problem
I would like to install the python-numpy in the Virtualenv environment. My system is Ubuntu 12.04, and my python is 2.7.5. First I installed the Virtualenv by ``` $ sudo apt-get install python-virtualenv ``` And then set up an environment by ``` $ mkdir myproject $ cd myproject $ virtualenv venv New python executable in venv/bin/python Installing distribute............done. ``` Activated it by ``` $ . venv/bin/activate ``` Installed python-numpy in the environment by ``` $ sudo apt-get install python-numpy ``` However, I tried to import numpy in python in the environment after all steps above. Python told me "No modules named numpy". Whereas, numpy could be imported in Python globally. I tried to remove and install many times but it does not work. I am a beginner of both Python and Linux.