SnapPy is a package for studying the topology and geometry of 3-manifolds, with a focus on hyperbolic structures. It is based on the SnapPea kernel written by Jeff Weeks.
There are two problems with this line: mkstemp or tempfile.TemporaryFile is favored over mktemp. 'ppm' shouldn't be added after the temporary file is created but passed as "suffix = '.ppm'" to the function.
https://github.com/3-manifolds/SnapPy/blob/7c1ea66f413a3ec759d82a50a1744a056a36b846/python/gui.py#L91
There are two problems with this line: mkstemp or tempfile.TemporaryFile is favored over mktemp. 'ppm' shouldn't be added after the temporary file is created but passed as "suffix = '.ppm'" to the function.