Re: [igraph] plotting problem with python

[Tamas Nepusz]

Dear Glenn,

It seems like the Python bindings of Cairo are not installed properly on
your machine -- igraph simply reports this when it says "plotting not
available".

I checked a working installation on Windows XP (32-bit) and the
following files should be present in
c:\python26\lib\site-packages\cairo:

__init__.py
_cairo.pyd
libcairo-2.dll
libexpat-1.dll
libfontconfig-1.dll
libpng14-14.dll
zlib1.dll

The error message you see means that Python finds __init__.py in the
cairo subfolder successfully, and it tries to import _cairo.pyd from
there. (.pyd files are like ordinary .dll files, Python just uses a
different extension to distinguish them from .dlls). Unfortunately the
import can fail for at least two reasons:

1) _cairo.pyd itself is missing
2) _cairo.pyd is there, but one of its dependencies is missing.

Unfortunately, the error message is the same in both cases. So, I'd do
the following:

1. Check whether all the files I mentioned above are in the
site-packages\cairo folder. If not, install them.

2. If they are all there, download Dependency Walker from
www.dependencywalker.com and open _cairo.pyd with it. Dependency Walker
should recursively traverse the dependency tree of _cairo.pyd and report
any other DLLs that you are missing.

-- 
Tamas