Python does not see pygraphviz

I have installed pygraphviz using easy_install But when i launch python i have an error:

>>>import pygraphviz as pgv
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named pygraphviz
>>> 

Using Ubuntu 12.04 and gnome-terminal.

Assuming that you're on Ubuntu please look at following steps

1. sudo apt-get install graphviz libgraphviz-dev pkg-config
2. Create and activate virtualenv if needed. The commands looks something like sudo apt-get install python-pip python-virtualenv
3. Run pip install pygraphviz
4. Run terminal and check by importing and see if it works

On Ubuntu 14.04, there is a problem in auto detecting graphviz library and include files. If you follow the steps below probably you'll be safe.

1) sudo apt-get install graphviz libgraphviz-dev pkg-config python-pip
2) pip install pygraphviz --install-option="--include-path=/usr/include/graphviz" --install-option="--library-path=/usr/lib/graphviz/" 

The quick and easy solution is:

sudo apt-get install -y python-pygraphviz

using pip will also work, but make sure you have graphviz, libgraphviz-dev, and pkg-config already installed.

sudo apt-get install -y graphviz libgraphviz-dev pkg-config python-pip
sudo pip install pygraphviz

On Mac OSX, the following did the trick for me:

pip install graphviz
pip install cgraph
export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig 
cd /usr/local/include/graphviz 
sudo ln -s . graphviz 
pip install pygraphviz

[As suggested, fixed typo from previously /urs/local/ to /usr/local/]

On Mac OSX El Capitan, Bart Theeten's solution works but there are two things you need to be careful. Initially, make sure that you installed graphviz on your computer. You can use homebrew:

brew install graphviz

Other thing is to make sure you add the path of packages to PYTHONPATH

export PYTHONPATH=$PYTHONPATH:/usr/local/lib/python2.7/site-packages/