Question

NOTE: USE PYTHON

CS160 Computer Science Lab 14

Working with lists, functions, and files

Objective:

Work with lists
Work with lists in functions Work with files

Assignment:
Part 1:
Write a program to create a text file which contains a sequence of test scores. Ask for scores until the user enters an empty value. This will require you to have the scores until the user enters -1.

After the scores have been entered, ask the user to enter a file name. If the user doesn’tnot enter a file name exit the program. If the user does enter a file name, write out the scores to the specified file. Then ask the user if they wish to create another data file. Continue on with this process until the user indicated they do not wish to create another data file or they do not enter a file name.

A sample session of this part might be:

Enter the scores, press enter to quit:
Score: 100 79 67 32 -1 - these will all be on separate lines

<>

Create another file? yes

Enter the scores, press enter to quit:
Score: 67 200 50 -1 – again, one number per line

<>
Create another file? no

After the above session, the contents of first file would be:

100 79 67 32

And the contents of the second file would be:

67 200 50

Make sure to create two or more files.

Part 2:

Write a program that will ask the user for a data file. Use one of the data files created from part 1. Each line of the file must contain a single value. Fill a list with the values from the file.

Once the list has been filled with values, the program should display, with appropriate labels, the largest value from the list, the smallest value from the list, and the average of the list (with 2 places after the decimal point). Then ask the user for a lower limit and an upper limit. Display all the values from the list that fall within that range.

The code to find the largest, smallest, and average must be done in value-returning functions. Do not use any built-in functions to find these values, write loops to implement these functions. The code to print out a range of scores must be done a function. The arguments for that function MUST be a list, a lower limit and an upper limit. The “matching values” function can print out values. For the rest of the program, only the main function will ask questions or print output.

A sample session of the part might be (using the sample data from above):

<>

 Largest score:     100
 Smallest score:     32
 Average score:   69.50

 Searching for values
 Enter the lower limit: 60
 Enter the upper limit: 80

 Matching values:
 79
 67

These values are calculated-in and returned-from functions. The values are printed in main.

These values are asked for in main and passed as arguments to the “matching values” function.

This information will be determined and printed inthe “matching values” function.

Answer 1

#########################################PART A #########################################

def get_test_scores():
    score_list=[]
    print('Enter the scores, press -1 to quit:')
    while True:
        score =int(input('Enter score: '))
        if score<0:break
        score_list.append(score)
    return score_list

def create_score_file(score_list,filename):
    with open(filename,'w') as outfile:
        for score in score_list:
            outfile.write(str(score)+'\n')

def main():
    file_number=1
    while True:
        scores = get_test_scores()
        create_score_file(scores,'score_'+str(file_number)+'.txt')
        file_number+=1
        another_file=input('Create another file? ')
        if another_file=='yes':continue
        else:break
main()

#########################################PART B #########################################
import os

def read_file_scores(filename):
    if os.path.isfile(filename) is not True:return None
    with open(filename,'r') as infile:
        return [int(score.strip()) for score in infile.readlines()]

def largest_score(scores):
    return  max(scores)

def smallest_score(scores):
    return  min(scores)

def average_score(scores):
    return sum(scores)/float(len(scores))


def print_matching_values(scores_list, lower_limit, upper_limit):
    print('Matchin values: ')
    for score in scores_list:
        if lower_limit<=score and score<=upper_limit:
            print(score)


def main():
    filename=input('Enter valid file name: ')
    scores_list=read_file_scores(filename)
    if scores_list is None:
        print('Invalid file entered. Program will terminate')
        return
    print('Largest score  :    {}'.format(largest_score(scores_list)))
    print('Smallest score :    {}'.format(smallest_score(scores_list)))
    print('Average score  :    {0:.2f}'.format(average_score(scores_list)))
    lower_limit=int(input('Enter the lower limit: '))
    upper_limit = int(input('Enter the upper limit: '))
    print_matching_values(scores_list,lower_limit,upper_limit)


main()

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