itemsize
Itemsize is the number of bytes used to store a single element of a data type in an array or buffer. It reflects the memory requirement of one element and is a key factor in calculating the total memory footprint of a collection of elements, as well as in understanding how data is laid out in memory.
In Python, the array module exposes an itemsize attribute on array objects, reporting the size of one
In NumPy, the size of one element is given by the dtype's itemsize (or by the ndarray.itemsize
To estimate memory usage, multiply the itemsize by the number of elements. Note that this gives the
Common values correspond to standard primitive types: 1 for int8/uint8 or bool, 2 for int16/uint16, 4 for