I installed python 3.7.3 using pyenv with env PYTHON_CONFIGURE_OPTS="--enable-framework" so that the dylib is included. Using the Leap.i, Leap.h, LeapMath.h, libLeap.dylib from SDK 2.3.1. The only edit I made was to Leap.i, replacing all the instances of %}} with }} to prevent line-indentation errors with swig. Then I successfully ran swig -c++ -python -o LeapPython.cpp -interface LeapPython Leap.i. Then I ran:
clang++ -arch x86_64 -I/path/to/my/include/python3.7m LeapPython.cpp libLeap.dylib /path/to/my/lib/python.dylib -shared -o LeapPython.so
I discarded the -arch i386 param from an example I saw, causing an error saying symbol not found or something. Otherwise no errors and LeapPython.so and Leap.py generated. When I import the new Leap.py file I get some errors:
NameError: name '__swig_getmethods__' is not defined and
NameError: name '_newclass' is not defined
I believe the Image, Frame and Mask classes each are attempting to access the above 2 items.