Question

Practice Activity -- Working with Counting Loops -- Part 2

Objective:

• to practice writing programs that use counting loops

Instructions:

This is the second part of a 2-part practice activity. Be sure to complete Part 1 before doing these exercises.

Write a Python program to solve each of the following in the order shown (in each pattern, the intention is that each number be printed on a separate line; no commas are required):

• Use a 'while' loop to create this pattern: -3, -2, -1, 0, 1, 2, 3, 4
• Use a 'for' loop to create the same pattern.
• Use a 'while' loop to create this pattern: 20, 15, 10, 5, 0, -5, -10
• Use a 'for' loop to create the same pattern.
• Use a 'while' loop to create this pattern: 36, 25, 16, 9, 4, 1, 0, 1, 4, 9, 16, 25, 36 (Hint: These are the squares of the numbers from -6 to 6. Use a loop to count -6, -5, -4, ... 6, but write out the square of the number instead of the number itself. (Optional: Use a 'for' loop to create the same pattern.)
• Use a 'while' loop to create this pattern: 10, 20, 40, 80, 160, 320, 640 (Hint: Can you see what the pattern is? You can use any statement that changes the value of the loop control variable as an update statement in a 'while' loop. How does this value get updated with each step in the pattern?)

Feel free to discuss any of these in the Discussion Forum. Upload your completed work as a single .py file with each of the exercises above completed in the order listed.

Answer 1

.I have implemented the required code in python.

And also provided the output of the respective code.

Source code:

Loopspart-2.py

# while loop to print -3, -2, -1, 0, 1, 2, 3, 4
i = -3
while i < 5:
  print(i)
  i += 1

# for loop to print -3, -2, -1, 0, 1, 2, 3, 4
x = range(-3, 5)
for n in x:
  print(n)

# while loop to print 20, 15, 10, 5, 0, -5, -10
i = 4
while i > -3:
  print(i*5)
  i -= 1

# for loop to print 20, 15, 10, 5, 0, -5, -10
start = 20
stop = -15
step = -5
for number in range(start, stop, step):
    print(number)

# while loop to print 36, 25, 16, 9, 4, 1, 0, 1, 4, 9, 16, 25, 36
i = -6
while i <= 6:
  print(i**2)
  i += 1
  
# while loop to print 10, 20, 40, 80, 160, 320, 640  
i=1
while i <=64 :
  print(i*10)
  i += i

Output:

-3
-2
-1
0
1
2
3
4
-3
-2
-1
0
1
2
3
4
20
15
10
5
0
-5
-10
20
15
10
5
0
-5
-10
36
25
16
9
4
1
0
1
4
9
16
25
36
10
20
40
80
160
320
640