I have this numpy array ‘dat’ which is a 3d array of size 2048 MB and of shape (512,1024,512) when I do asizeof.asizeof(dat) from pympler, I get the error: ValueError: invalid option: reset(base=-2147483504) but in a ipython session if I have defined any numpy array prior to this, then the asizeof.asizeof(dat) works without the error and I get 4096 MB instead of the actual 2048 MB. Now I understand pympler might include the buffer size, metadata etc but 2 GB for such things is too much! Kindly help me here!