how do i use this code to find the top 5 max numbers in a file if each number has a string next to it?

Question

from heapq import nlargest

with open("winnernum.txt", "r") as f:
   numbers = [float(line.rstrip()) for line in f.readlines()]
   largest = nlargest(5, numbers)    
print(largest)

I have tested this code and it works if there is no string next to each number because you can't turn a string into a float i assume. The string is there because each highscore has a username next to it. the program should print the winner's name and their score for the top 5 highest scoring players.

you can probably split the input .. and only take the digits from that and compute it. — Yatish Kadam, Dec 27 '19 at 18:37
depending on the format of the line, so that's why show us sample input / desired output — Boendal, Dec 27 '19 at 18:39
@FilipHaglund the contents of the file is usually: ['katy'] 30 — katy, Dec 27 '19 at 18:39
All ways store the score of the player at start of the sentence. Then split them — Ch3steR, Dec 27 '19 at 18:40
split("]") should give you a list .. witht eh score as the second item... — Yatish Kadam, Dec 27 '19 at 18:40
If you search in your browser for "Python string handling" and specifically the `split` method, you'll find references that can explain this much better than we can manage here. — Prune, Dec 27 '19 at 18:42
@YatishKadam could you please show me this and where you would put it in my code? Thank you! — katy, Dec 27 '19 at 18:43
Welcome to StackOverflow. [On topic](https://stackoverflow.com/help/on-topic), [how to ask](https://stackoverflow.com/help/how-to-ask), and ... [the perfect question](https://codeblog.jonskeet.uk/2010/08/29/writing-the-perfect-question/) apply here. StackOverflow is a knowledge base for *specific* programming problems -- not intended as a tutorial resource. You will likely get references to particular tools, such as `split`. As implied in the posting guidelines, we expect you to then research those tools and tutorials on your own. — Prune, Dec 27 '19 at 18:44
Also, as an exercise for future postings, you might try to edit this one to conform better: Give us input samples, show the desired output, and your coding attempt. You've made a decent start. — Prune, Dec 27 '19 at 18:45

Boendal · Answer 1 · 2019-12-27T18:54:20.290

0

A running example if the input looks like described in the comment:

from heapq import nlargest

test_str = """ ['katy'] 30
['max'] 45
['A'] 31
['B'] 4
['D'] 1
['C'] 15
['E'] 333"""

numbers = [float(line.rstrip().split("]")[1]) for line in test_str.split("\n")]
largest = nlargest(5, numbers)
print(largest)

In your case you would do it like this:

from heapq import nlargest

with open("winnernum.txt", "r") as f:
   numbers = [float(line.rstrip().split("]")[1]) for line in f.readlines()]
   largest = nlargest(5, numbers)    
print(largest)

Edit

To avoid empty lines or lines without "]"

numbers = []
with open("winnernum.txt", "r") as f:
    for line in f.readlines():
        split = line.rstrip().split("]")
        if len(split) > 1:
            numbers.append(float(split[1]))

edited Dec 27 '19 at 18:54

answered Dec 27 '19 at 18:44

Boendal

2,496
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IndexError: list index out of range – katy Dec 27 '19 at 18:50
1

@katy then you have an empty line in your file or a line without a ] in which case there is no split. So check your file. – Boendal Dec 27 '19 at 18:51
@katy or you can see my edit, so you can avoid empty lines. – Boendal Dec 27 '19 at 18:54

Ch3steR · Accepted Answer · 2019-12-27T22:18:40.187

If test.txt is

green 12
blue 13
red 14
yellow 15
hello 16
green1 122
blue1 132
red1 142
yellow1 152
hello1 162
green2 121
blue2 131
red2 141
yellow2 151
hello2 161

Code:

from heapq import nlargest
with open("test.txt",'r')as f:
    c={}
    for l in f:
        c[l.split("]")[0]]=(float(l.split("]")[1]))
    largest=nlargest(5,list(c.values()))
    print(c)
    print(largest)
    for x in largest:
        for i in c:
            if c[i] == x:
                print(i[1:],x)

output:

{'green': 12.0, 'blue': 13.0, 'red': 14.0, 'yellow': 15.0, 'hello': 16.0, 'green1': 122.0, 'blue1': 132.0, 'red1': 142.0, 'yellow1': 152.0, 'hello1': 162.0, 'green2': 121.0, 'blue2': 131.0, 'red2': 141.0, 'yellow2': 151.0, 'hello2': 161.0}
[162.0, 161.0, 152.0, 151.0, 142.0]
hello1 162
hello2 161
yellow1 152
yellow2 151
red1 142

Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackoverflow.com/rooms/204971/discussion-on-answer-by-ch3ster-how-do-i-use-this-code-to-find-the-top-5-max-num). — Samuel Liew, Dec 27 '19 at 22:51

how do i use this code to find the top 5 max numbers in a file if each number has a string next to it?

2 Answers2

Edit