RPi.GPIO not found in virtual environment

Question

I'm working on a python project based on OpenCV .. after installing the opencv from this link : http://www.pyimagesearch.com/2016/04/18/install-guide-raspberry-pi-3-raspbian-jessie-opencv-3/ And when i'm in the virtual environment and after importing RPi.GPIO i get that no module named RPi.GPIO

But When i'm outside the virtual environment the RPi.GPIO works properly I have raspbian Jessy on a Raspberry pi 3

Answer 1

The problem is that you don't have the GPIO module installed in your virtual environment. To correct this, run the following from within your virtual environment:

for Python 2

pip install RPi.GPIO

or for Python 3

pip3 install RPi.GPIO

This will install the module where your virtual environment can find it.

One of the features of virtual environments is that they allow you to manage modules on a project by project basis and avoid conflicts with other projects (e.g. project A requires version 1 and project B requires version 3 of the same module). More info on virtual environments and modules can be found in the Python documentation. Tutsplus has a nice tutorial on Python Virtual Environments

Answer 2

As per Steve's answer:

http://www.pyimagesearch.com/2016/05/02/accessing-rpi-gpio-and-gpio-zero-with-opencv-python/

To cite that author:

The reason for this problem is that RPi.GPIO/GPIO Zero were not installed into your Python virtual environment! To fix this issue, all you need to do is use pip to install them into your virtual environment — from there, you’ll be good to go.

But to be honest with you, I don’t think that’s the real issue here!

The real problem is not having a sufficient understanding of what Python virtual environments are and why we use them...