Python .txt file & while loop

Question

Question:

1. In main, create an empty list.
2. Open the file named scores.txt and use a while loop that can detect the end of file to read the scores, and add them to the list and then close the file.
3. Call the showscores function with the list of scores as sole argument.
4. Inside the showscores function, process the list of scores.
5. Print out the average score accurate to two decimal places.

This is scores.txt which contains a list of 5 numbers. The numbers in the file are list vertically like so:

                                          86

                                          92

                                          77

                                          83

                                          96

I have the below code now, but keep getting thiese errors:

line 19, in main()

line 17, in main showscores(scores)

line 2, in showscores sum_scores = sum(scores)

TypeError: unsupported operand type(s) for +: 'int' and 'str'

def showscores(scores):
sum_scores = sum(scores)
average = float(sum_scores // len(scores))
print ("The scores are: " + str(scores))
print ("Average score: " + str(average))


def main():
scores = []
scores_file = open("scores.txt", 'r')
line_list = list(scores_file.readlines())
i = 0
while i < len(line_list):
    scores.append(line_list[i])
    i += 1
scores_file.close()
showscores(scores)

main()

Answer 1

No one here is really helping him. It is pretty obvious that OP just started learning programming and is having some issue figuring it out. (Right?)

Giving him all made solutions just to get some rep won't do.

I think OP is faced with an exercise or homework and has defined steps to follow.

OP, it is hard at first but it is going to be ok.

Describing the parts that seem to cause you more troubles:

• You need to open the file, for this, you can read the link that sshashank124 gave you ( http://www.tutorialspoint.com/python/python_files_io.htm ).
• The while expects from you to read the text file line by line (that is why you need a while loop, to repeat the same action for each line). For each line, add its content to the list you previously created.
• Give that list to the function showscores (that you need to code as well), and if I understand the directions you received, you "process" the data there. Because what is in your current list? A string of each line. Process it so you turn it into, more practical, actual numbers.
• From there, you can now calculate what has been asked to you (average, etc) and display it.

For examples of code, check the other answers. Even though they might trouble you because they, IMHO, don't seem "noob friendly". Don't forget to use for favorite search engine if you get any issue, read the documentation, etc.

EDIT: As you seem to specifically struggle with the while loop. Here is a small code showcasing it.

Before please check out that small tutorial to understand the basic behind it: http://www.afterhoursprogramming.com/tutorial/Python/While-Loop/

So instead of the magic for loop that does it all for you, here is how you'd do it using while:

def main():
    scores = []

    scores_file = open("path to scores.txt", 'r')

    line_list = list(scores_files.readlines())

    i = 0
    while i < len(line_list):
        scores.append(line_list[i])
        i += 1

    showscores(scores)

Answer 2

I have tried this and it works:

def showscores(scores):
    sum_scores = sum(scores)
    average = float(sum_scores // len(scores))
    print ("The scores are: " + str(scores))
    print ("Average score: " + str(average))



def main():
    f = open("PATH TO YOUR FILE", 'r')
    content = list(f.readlines())
    scores = []
    for x in content:
        scores.append(int(x.replace(" ", "")))

    showscores(scores)

main()

Hope this works for you

Answer 3

Solution with Exception Handling.

Code:

import os

def showscores(scores):
    """ average """
    #- Get Total sum from the scroes list by sum in-build function. 
    total = sum(scores)
    print "Debug 4:", total
    #- Get average and handle dividing by zero  exception. 
    try:
        avg = total/float(len(scores))
    except ZeroDivisionError:
        avg = 0.0

    #- Print result.
    print "average of scores is= %.2f"%avg

    return

def main():
    """ Get Scores from the file."""

    file_name = "scores.txt"
    #- Check file is exists or not.
    if not os.path.isfile(file_name):
        print "Input file is not found."
        return []

    scores = []
    #- Read file content.
    with open(file_name, "rb") as fp:
        #- Iterate file upto EOF line
        while True:
            line = fp.readline()
            if not line: 
                break
            #- Type Casting because line is string data type.
            try:
                scores.append(int(line.strip()))
            except ValueError:
                print "Exception during Type Casting.- Input %s"%line

    return scores


if __name__=="__main__":
    scores = main()
    showscores(scores)

Output:

Exception during Type Casting.- Input 

Exception during Type Casting.- Input 

Exception during Type Casting.- Input 

Exception during Type Casting.- Input 

Debug 4: 434
average of scores is= 86.80

---

Use with statement and map function:

#- Read file content.
with open(file_name, "rb") as fp:
    content = fp.read()

#- Get all numbers from the file content by RE and map.
scores = map(int, re.findall("\d+", content))


return scores

Answer 4

This has been completed. This is what ended up working:

def showscores(scores):
    sum_scores = sum(scores)
    average = float(sum_scores // len(scores))
    print ("The scores are: " + str(scores))
    print ("Average score: " + str(average))


def main():
    scores = []
    scores_file = open('scores.txt', 'r')
    line_list = list(scores_file.readlines())
    scores_file.close()
    i = 0
    while i < len(line_list):
        scores.append(int(line_list[i].strip()))
        i += 1

    showscores(scores)

main()