While Loop Exercises

6.3. While Loop Exercises#

6.3.1. Exercise 1#

Write a program that takes integers from the user and returns the average. Use a while loop and make an empty string the stop criteria.

Hide code cell source 
summed_values = 0  # a container to store the sum of interger values collected
number_count = 0  # a container to store the number of integer values collected

input_string = input('Enter an integer. Enter nothing to quit: ')

while input_string:
    summed_values += int(input_string)
    number_count += 1
    input_string = input('Enter an integer. Enter nothing to quit: ')


average = summed_values / number_count

print('The average of %d numbers is %f' %(number_count, summed_values))

6.3.2. Exercise 2#

Write a program that takes integers from the user and returns the average. Use a while loop and make negative number the stop criteria.

Hide code cell source 
summed_values = 0  # a container to store the sum of interger values collected
number_count = 0  # a container to store the number of integer values collected

number = int(input('Enter an integer. Enter negative number to quit: '))

while number >=0:
    summed_values += int(number)
    number_count += 1
    number = int(input('Enter an integer. Enter nothing to quit: '))


average = summed_values / number_count

print('The average of %d numbers is %f' %(number_count, summed_values))

6.3.3. Exercise 3#

Write a program that takes test grades from the user and returns their average and the letter grade of the average.Use a while loop and make negative number the stop criteria. A >=90 B 80-89 C 70-79 D 60-69 F 59 or less

Hide code cell source 
test_grades = 0  # a container to store the sum of interger values collected
number_tests = 0  # a container to store the number of integer values collected

number = int(input('Enter a test grade. Enter negative number to quit: '))

while number >=0:
    test_grades += int(number)
    number_tests += 1
    number = int(input('Enter a test grade. Enter negative number to quit: '))


average = test_grades / number_tests


if   90 <= average:
    letter_grade = 'A'
elif 80 <= average <= 89:
    letter_grade = 'B'
elif 70 <= average <= 79:
    letter_grade = 'C'
elif 60 <= average <= 69:
    letter_grade = 'D'
elif 60 >= average:
    letter_grade = 'F'


print(average, letter_grade)

6.3.4. Exercise 4#

Write a program that takes an integer and counts down to zero – print the value

Hide code cell source 
number = int(input('Enter a starting number: '))

while number >= 0:
    print(number)
    number -= 1

6.3.5. Exercise 5#

6.4. Write a program that takes an integer number and outputs all the even numbers starting from 0 to the number#

Hide code cell source 
end_number = int(input('Enter an integer number: '))
current_number = 0
while current_number <= end_number:
    if current_number % 2 == 0:
        print(current_number)
    current_number += 1
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