python - igraph plot not available (cairo already installed)
Question: I've installed py2cairo using brew, but keep getting errors when trying to
plot with igraph. I get the following error:

    
    
    >>> import igraph as ig
    >>> from igraph import *
    >>> UG = ig.Graph()
    >>> UG.add_vertex('a')
    >>> UG.add_vertex('b')
    >>> UG.add_vertex('c')
    >>> UG.add_vertex('d')
    >>> UG.add_edge('a','d')
    >>> UG.add_edge('a','c')
    >>> UG.add_edge('b','c')
    >>> UG.add_edge('b','a')
    
    >>> layout = UG.layout_kamada_kawai()
    >>> plot(UG,layout = layout)
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
      File ".../anaconda/lib/python2.7/site-packages/igraph/drawing/__init__.py", line 427, in plot
        result = Plot(target, bbox, background="white")
      File ".../anaconda/lib/python2.7/site-packages/igraph/drawing/__init__.py", line 122, in __init__
        self._surface_was_created = not isinstance(target, cairo.Surface)
      File ".../anaconda/lib/python2.7/site-packages/igraph/drawing/utils.py", line 396, in __getattr__
        raise TypeError("plotting not available")
    TypeError: plotting not available
    


Answer: `brew` probably installs `py2cairo` for its own Python, while you are running
igraph under Anaconda Python. A module installed for one Python distribution
on your machine will not appear magically under the other Python distribution,
so you'll either have to get `py2cairo` for Anaconda Python or compile the
Python interface of igraph for Homebrew's Python.

