correct syntax for range() code example

Example 1: python range

# range(start, stop, step)
  # start = (can be ommitted) index to begin at (INCLUSIVE)
  # stop = generate numbers up to, but not including this number (EXCLUSIVE)
  # step = (can be omitted) difference between each number in the sequence

# idx:  0	1	2	3 	4
# arr:  19	5	3	22	13
  
arr = [19,5,3,22,13]

# range(stop)
for i in range(len(arr)):
    print(arr[i]) # prints: 19, 5, 3, 22, 13

# range(start, stop)
for i in range(2, len(arr)):
    print(arr[i]) # prints: 3, 22, 13
    
# range(start, stop, step)
for i in range(0, len(arr), 2):
    print(arr[i]) # prints: 19, 3, 13
    
# reverse:
for i in range(len(arr)-1, -1, -1):
    print(arr[i])

Example 2: range parameters python

arr_data=[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20] 
user = int(input("Enter the product of numbers: ")) 
for i in range(0,20,1): 
    a = arr_data[i] 
    for t in range(0,20,1): 
        b = arr_data[t] 
        if (a*b) == user: 
            print(a,"x",b,"=",user) 
        else: 
            pass