Why Can't Objgraph Capture The Growth Of Np.array()?

See the code: import objgraph import numpy as np objgraph.show_growth() j = 20 y = [] for i in range(5): for l in range(j): y.append(np.array([np.random.randint(500),np

Solution 1:

I'm not that familiar with objgraph specifically, but I think the same issue applies to other Python heap analysis tools such as heapy.

Numpy arrays are implemented in C, and do their own reference counting by internally calling Py_INCREF and Py_DECREF. As such, they are not tracked by the Python garbage collector. Tools like heapy and (presumably) objgraph use the Python garbage collector to track references to objects, so as a result numpy arrays are invisible to them.