demo_python/d_numpy.py where(), arange(), amax()
demo_python/d_numpy.py -- where(condition, x, y) if non-scalar vars with diff shape , lead to shape mismatch
demo_python/d_numpy.py d_type
numpy.where - float ndarr, int ndarr, nscalar
numpy.ones
demo_python/d_os.py os.path.exists()