python data type not understood code example

Example 1: np.zeros data type not understood

mmatrix = np.zeros((nrows, ncols))

Example 2: np.zeros data type not understood

import numpy as np
dim = 3 # number of entries
shp = (dim, 1) # shape tuple
x = np.zeros(shp) # second argument 'dtype' is not used, default is 'float'
print(x)