Member Avatar for minimee120

Hi all I need help with the final part of my practice problems for class, if anyone who can show me what to do it would be greatly appreciated!!

Write a program that incorporates the following functionality:

1) Prompt the user for a series of names and scores.

2) Store each name and score pair in a dictionary (indexed by score).

3) Write the names and scores to a text file - one pair per line.

4) Read the file line by line and insert each name/score pair into a new dictionary.

5) Display the results. For example:

Mark 74
Jill 83
Jack 44
etc.

6) Sort the results by score.

7) Display the sorted results in descending (or non-ascending) order. For example:

Jill 83
Mark 74
Jack 44
etc.

Here's My Code as of now:

def getScore(scores):
    name = input('Please enter a name: ')
    score = int(input('Please enter ' + name + '\'s score: '))
    scores[score] = name

def getScores(scores):
    keepgoing = True

    while(keepgoing):
        getScore(myscores)
        reply = input('Do you want to enter another score? ')
        if(reply == 'y'):
            continue
        else:
            keepgoing = False

def saveScores(scores, filename):
    out_file = open(filename, "wt")
    for num in scores.keys():
        out_file.write(str(num) + " " + scores[num] + "\n")
    out_file.close()

def readScores(scores, filename):
    file = open(filename)
    name = ''
    score = ''
    for line in file:
        score, name = line.split()
        scores[int(score)] = name

infile = open("scores.txt","r")



for line in infile:
    values = line.split()
    scores[values[0]] = values[1]
    print('Name: ', values[1], 'score', values[0])
infile.close()

for key in sorted(scores.keys(), reverse=True):
    print(scores[key], key)


def printScores(scores):
    for num in scores.keys():
            print(scores[num] + " " + str(num))

def printSorted(scores):
    for num in sorted(scores.keys(), reverse=True):
            print(scores[num] + " " + str(num))


myscores = {}
getScores(myscores)
saveScores(myscores, 'scores.txt')
newscores = {}
readScores(newscores, 'scores.txt')
print(newscores)
print('==============================')
print(sorted(newscores.items(), reverse=True))
print('==============================')
print('==============================')
printScores(newscores)
print('==============================')
printSorted(newscores)
print('==============================')

This is my text file(scores.txt)
84 frank
76 mary
52 john

I am looking for help with numbers 6 and 7 as my professor really hasn't taught us how to do these steps!

Thank You!

Edited by vegaseat because: code tags
  • 3 Contributors
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  • 1 Day Discussion Span
  • Latest Post Latest Post by Lardmeister

Dani AI

Generated

Using the score as a dictionary key is what’s tripping things up: dict keys must be unique, so equal scores overwrite earlier entries. As suggested, collecting names in a list per score fixes that. Also make sure scores are numeric (convert to int on read) so sorting is numeric rather than lexicographic. ’s itemgetter idea is handy when working with lists of pairs.

One approach that honors “indexed by score” is to map each score to a list of names (collections.defaultdict(list)). Parse each input line so the last token is treated as the score (this allows names with spaces), convert that token to int, then append the name. Finally iterate the integer keys in sorted(..., reverse=True) and print each name with its score.

from collections import defaultdict

by_score = defaultdict(list)

# assume 'lines' is the lines read from the file
for line in lines:
    line = line.strip()
    if not line:
        continue
    name, score = line.rsplit(' ', 1)    # split on last space
    by_score[int(score)].append(name)

for score in sorted(by_score.keys(), reverse=True):
    for name in by_score[score]:
        print(name, score)

An alternative is to keep a list of (score, name) tuples and sort that list; this sidesteps collisions and is straightforward to print. Use operator.itemgetter(0) or a lambda as the sort key and pass reverse=True for descending order.

from operator import itemgetter

pairs = [(84, 'frank'), (76, 'mary'), (52, 'john')]
for score, name in sorted(pairs, key=itemgetter(0), reverse=True):
    print(name, score)

Operational tips: use with open(...) for file I/O, pick a clear delimiter (tab or CSV) if names can contain spaces, convert score strings to int immediately, and accept duplicate scores by storing lists (or using the tuple-list approach) so no data is lost.

Recommended Answers

All 2 Replies

Member Avatar for hughesadam_87

For 6 and 7, you should look into the module itemgetter() (Do a ctrl+f for getter on this page: http://docs.python.org/library/operator.html)

If you have simple items in a list, for example a list of ints:

mylist=[1,2,5,3,7,8]

Then you can use simply mylist.sort() to sort them. If you have strings, it will sort them alphabetically. But if you have more complex data types like in your case, a person and a score, you can store them in a list of tuples aka:

mylist=[(Bill, 93), (Adam, 100), (Josh,32)]

(Giving myself 100% of course)... then you can use the itemgetter to sort these by the second value in the tuple. This is a handy import because it can be used for even more complex tuples, like a tuple of 3 names and 15 scores.

Once you have the new sorted object, just use obj.reverse() to output it in the opposite order (ascending or descending).

Member Avatar for Lardmeister

Now remember that the key of a dictionary has to be unique. Names with the same score have to processed so the names appear in a list.

Here is an example how to handle key collisions:

# has 2 names with matching scores
data_str = """\
Mark 50
Adam 20
Tony 70
Frank 50"""

fname = "score_file.txt"
# write the data file
with open(fname, "w") as fout:
    fout.write(data_str)

# read the data file back in
# and convert to a score:name dictionary
score_dict = {}
for line in open(fname):
    #line = line.strip()
    name, score = line.split()
    # this will not handle matching scores
    #score_dict[int(score)] = name
    # this handles score collisions
    score_dict.setdefault(score, []).append(name)

print(score_dict)

'''
{'20': ['Adam'], '50': ['Mark', 'Frank'], '70': ['Tony']}
'''
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