NumPy - Random Numbers

Pseudo Random and True Random

random number does NOT mean a different number every time
random means something that can not be predicted logically

Generate Random Number

NumPy offers the random module to work with random numbers generate a random integer from 0 to 100

from numpy import random

x = random.randint(100)
print(x)

Generate Random Float

the random module's rand() method returns a random float between 0 and 1

from numpy import random

x = random.rand()
print(x)

Generate Random Array

Integers

can use the two methods above to make random arrays
the randint() method takes a size parameter specifying the shape of an array
generate a 1-D array containing 5 random integers from 0 to 100

from numpy import random

x=random.randint(100, size=(5))
print(x)

Generate Random Number From Array

the choice() method allows you to generate a random value based on an array of values
takes an array as a parameter and randomly returns one of the values

from numpy import random

x = random.choice([3, 5, 7, 9])
print(x)

method can also return an array of values
size parameter can specify the shape of the array
generate a 2-D array that consists of the values in the array parameter

from numpy import random

x = random.choice([3, 5, 7, 9], size=(3, 5))
print(x)

set replace parameter to False to keep duplicates out of the result

arr = np.random.choice(arr, size=(20), replace=False)