pythonOCC comes with importers/exporters for the most commonly used standard data files format in engineering: STEP (AP203 and AP214), IGES, STL (ascii/binary) and VRML. After the import is successfull, the resulting shape can be handled as a native topology/geometry, i.e. you can use boolean operations, shape fixing, traverse topology etc. The following screenshots show the import of the STEP file describing the i6400r ABB robot (courtesy of the ABB, STEP file downloaded from the ABB Library).
STEP file import (6.1Mb, 75895 entities)