Geometry package

[Justin Pearson]

Hi all,

I'm looking for a geometry package in Python; something that will let
me define line segments, and can tell me if two line segments
intersect. It would be nice if the lines could be defined in n-space
(rather than be confined to 2 or 3 dimensions), but this is not a hard
constraint. Other functionality might include support for polygons,
convex hulls, etc.

I've searched Pypi and found a package called Shapely, but when I
followed its installation instructions, it threw a bunch of errors and
tried to re-install Python :(.

Is there a well-known geometry package I'm missing?

Thanks for your help,
Justin