Example for using the PyDataMem_SetEventHook to track allocations inside numpy.
alloc_hook.pyx implements a hook in Cython that calls back into a python
function. track_allocations.py uses it for a simple listing of allocations.
It can be built with the setup.py file in this folder.
Note that since Python 3.6 the builtin tracemalloc module can be used to
track allocations inside numpy.
Numpy places its CPU memory allocations into the np.lib.tracemalloc_domain
domain.
See https://docs.python.org/3/library/tracemalloc.html.