To install Python in Windows follow previous article here

To install NumPy library follow this YouTube video

### First of all, after installing Numpy library, use the following import convention:

>>> import numpy as np

### To create NumPy arrays

>>> a = np.array([1,2,3])

>>> b = np.array([(1.5,2,3), (4,5,6)], dtype = float)

>>> c = np.array([[(1.5,2,3), (4,5,6)], [(3,2,1), (4,5,6)]], dtype = float)

here, a is 1D – array, b is 2D array and c is 3D array

**Use of initial place holders:**

>>> np.zeros((3,4))Create an array of zeros

>>> np.ones((2,3,4),dtype=np.int16)Create an array of ones

>>> d = np.arange(10,25,5)Create an array of evenly spaced values (step value)

>>> np.linspace(0,2,9)Create an array of evenly spaced values (number of samples)

>>> e = np.full((2,2),7)Create a constant array

>>> f = np.eye(2)Create a 2X2 identity matrix

>>> np.random.random((2,2))Create an array with random values

>>> np.empty((3,2))Create an empty array

**Basic I/O **

**Saving & Loading On Disk**

>>> np.save(‘my_array’, a)

>>> np.savez(‘array.npz’, a, b)

>>> np.load(‘my_array.npy’)

**Saving and Loading Text Files**

>>> np.loadtxt(“myfile.txt”)

>>> np.genfromtxt(“my_file.csv”, delimiter=’,’)

>>> np.savetxt(“myarray.txt”, a, delimiter=” “)

### To Inspect Your array

>>> a.shape Array dimensions

>>> len(a) Length of array

>>> b.ndim Number of array dimensions

>>> e.size Number of array elements

>>> b.dtype Data type of array elements

>>> b.dtype.name Name of data type

>>> b.astype(int) Convert an array to a different type