Python if else, for loop, and range() Exercise with Solutions

To decide or control the flow of a program, we have branching and looping techniques in Python. To perform decision-making, we use the if-else statement in Python.

To iterate over a sequence of elements, we use for loop, and when we want to iterate a block of code repeatedly, as long as the condition is true, we use the while loop.

We often use a loop, and if-else statement in our program, so a good understanding of it is necessary.

This Python loop exercise aims to help Python developers to learn and practice if-else conditions, for loop, range() function, and while loop. All questions are tested on Python 3.

This Python loop exercise include the following: –

• The exercise contains 18 questions and solutions provided for each question.
• This exercise is nothing but an assignment to solve, where you can solve and practice different looping techniques programs, and challenges.

Let us know if you have any alternative solutions. It will help other developers.

Use Online Code Editor to solve exercise questions.

Exercise 1: Print First 10 natural numbers using while loop

Expected output:

0
1
2
3
4
5
6
7
8
9
10

i = 0
while i <= 10:
    print(i)
    i += 1

Exercise 2: Print the following pattern

1 
1 2 
1 2 3 
1 2 3 4 
1 2 3 4 5

Refer: Print Patterns In Python

print("Second Number Pattern ")
lastNumber = 6
for row in range(1, lastNumber):
    for column in range(1, row + 1):
        print(column, end=' ')
    print("")

Exercise 3: Accept number from user and calculate the sum of all number from 1 to a given number

For example, if user entered 10 the output should be 55.

sum1 = 0
n = int(input("Please enter number "))
for i in range(1, n + 1, 1):
    sum1 += i
print("\n")
print("Sum is: ", sum1)

Exercise 4: Print multiplication table of a given number

For example, num = 2 so the output should be

2
4
6
8
10
12
14
16
18
20

n = 2
for i in range(1, 11, 1):
    product = n*i
    print(product)

Exercise 5: Given a list, iterate it, and display numbers divisible by five, and if you find a number greater than 150, stop the loop iteration.

list1 = [12, 15, 32, 42, 55, 75, 122, 132, 150, 180, 200]

Expected output:

15
55
75
150

list1 = [12, 15, 32, 42, 55, 75, 122, 132, 150, 180, 200]
for item in list1:
    if (item > 150):
        break
    if(item % 5 == 0):
        print(item)

Exercise 6: Given a number count the total number of digits in a number

For example, the number is 75869, so the output should be 5.

num = 75869
count = 0
while num != 0:
    num //= 10
    count+= 1
print("Total digits are: ", count)

Exercise 7: Print the following pattern using for loop

5 4 3 2 1 
4 3 2 1 
3 2 1 
2 1 
1

n = 5
k = 5
for i in range(0,n+1):
    for j in range(k-i,0,-1):
        print(j,end=' ')
    print()

Exercise 8: Reverse the following list using for loop

list1 = [10, 20, 30, 40, 50]

Expected output:

50
40
30
20
10

list1 = [10, 20, 30, 40, 50]
start = len(list1) - 1
stop = -1
step = -1
for i in range(start, stop, step) :
    print(list1[i])

Exercise 9: Display numbers from -10 to -1 using for loop

Expected output:

-10
-9
-8
-7
-6
-5
-4
-3
-2
-1

for num in range(-10, 0, 1):
    print(num)

Exercise 10: Display a message “Done” after successful execution of for loop

For example, the following loop will execute without any error.

for i in range(5):
    print(i)

So the Expected output should be:

0
1
2
3
4
Done!

for i in range(5):
    print(i)
else:
    print("Done!")

Exercise 11: Write a program to display all prime numbers within a range

Note: A Prime Number is a whole number that cannot be made by multiplying other whole numbers

Examples:

• 6 is not a Prime Number because it can be made by 2×3 = 6
• 37 is a Prime Number because no other whole numbers multiply together to make it.

Given:

start = 25
end = 50

Expected output:

Prime numbers between 25 and 50 are:
29
31
37
41
43
47

start = 25
end = 50
print("Prime numbers between", start, "and", end, "are:")

for num in range(start, end + 1):
    # all prime numbers are greater than 1
    # if number is less than or equal to 1, it is not prime
    if num > 1:
        for i in range(2, num):
            # check for factors
            if (num % i) == 0:
                # not a prime number so break inner loop and
                # look for next number
                break
        else:
            print(num)

Exercise 12: Display Fibonacci series up to 10 terms

Expected output:

Fibonacci sequence:
0  1  1  2  3  5  8  13  21  34

terms = 10
# first two terms
num1, num2 = 0, 1
count = 0

print("Fibonacci sequence:")
while count < terms:
    print(num1, end="  ")
    temp = num1 + num2
    # update values
    num1 = num2
    num2 = temp
    count += 1

Exercise 13: Write a loop to find the factorial of any number

The factorial (symbol: !) means to multiply all whole numbers from the chosen number down to 1.

For example: calculate the factorial of 5

5! = 5 × 4 × 3 × 2 × 1 = 120

Expected output:

120

num = 5
factorial = 1
if num < 0:
    print("Factorial does not exist for negative numbers")
elif num == 0:
    print("The factorial of 0 is 1")
else:
    for i in range(1, num + 1):
        factorial = factorial * i
    print("The factorial of", num, "is", factorial)

Exercise 14: Reverse a given integer number

Given:

76542

Expected output:

24567

num = 76542
reverse_number = 0
print("Given Number ", num)
while num > 0:
    reminder = num % 10
    reverse_number = (reverse_number * 10) + reminder
    num = num // 10
print("Revered Number ", reverse_number)

Exercise 15: Use a loop to display elements from a given list that are present at odd index positions

Given:

my_list = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100]

Note: list index always starts at 0

Expected output:

20 40 60 80 100

my_list = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100]
for i in my_list[1::2]:
    print(i, end=" ")

Exercise 16: Display the cube of the number up to a given integer

Given:

input_number = 6

Expected output:

Current Number is : 1  and the cube is 1
Current Number is : 2  and the cube is 8
Current Number is : 3  and the cube is 27
Current Number is : 4  and the cube is 64
Current Number is : 5  and the cube is 125
Current Number is : 6  and the cube is 216

input_number = 6
for i in range(1, input_number + 1):
    print("Current Number is :", i, " and the cube is", (i * i * i))

Exercise 17: Find the sum of the series 2 +22 + 222 + 2222 + .. n terms

Given:

number_of_terms = 5

So series will become 2 + 22 + 222 + 2222 + 22222

Expected output:

24690

number_of_terms = 5
start = 2
sum = 0
for i in range(0, number_of_terms):
    print(start, end=" ")
    sum += start
    start = (start * 10) + 2
print("\nSum of above series is:", sum)

Exercise 18: Print the following pattern

* 
* * 
* * * 
* * * * 
* * * * * 
* * * * 
* * * 
* * 
*

Refer: Print Patterns In Python

rows = 5
for i in range(0, rows):
    for j in range(0, i + 1):
        print("*", end=' ')
    print("\r")

for i in range(rows, 0, -1):
    for j in range(0, i - 1):
        print("*", end=' ')
    print("\r")