In 2.2.2. (Buffers), python code snippet:

data = numpy.zeros(4, dtype = [ ("position", np.float32, 3),
                                ("color",    np.float32, 4)] )

The first time a numpy structure is used, it is called with the name numpy (numpy.zeros), while later numpy structures are called with the abbreviation np (np.float32, specifically).

These calls should all be uniform. As the preface states that numpy is imported as import numpy as np, numpy.zeros should be changed to np.zeros.

Edit: this also repeats in 2.2.3 (Variables).