This is one of those questions with no really satisfying answer. But take a look at these:
- https://www.ibm.com/developerworks/library/os-physicsengines/.
- pyODE (ODE exported to python), but latest is from 2010 and supports up to python 2.6; the C++ side seems to be actively maintained
- newton which has python bindings but latest release (even C++ backend) again not updated since 4/2011;
- bullet which is actively maintained at the C++ level but the python bindings have not been updated in about a year and down't know how comprehensive and stable
- reactphysics3d is C++ but actively maintained: need to create python bindings
- havoc: not free and no python bindings, but appears most powerful
If you are willing to learn SWIG (www.swig.org) you can probably create your own Python binding for the parts of Bullet or PyODE or reactphysics3d that you want. Don't know about Havoc.