As noted above, NumPy arrays behave a lot like other Python objects, for the sake of convenience. For instance, they can be indexed like lists; arr[0] accesses the first element of a NumPy array.

By default in NumPy and Cython, arrays are laid out in a contiguous fashion compatible with C. ::1 is our last element in the above sample, so we use int[:,::1] as our signature.

Arrays in Python give you a huge amount of flexibility for storing, organizing, and accessing data. This is crucial, not least because of Python’s popularity for use in data science.