Selecting random scores from a .txt file and finding their average (Python)

user_8652137 0
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I've been trying to select scores at random from a .txt file and then finding the average of these randomly selected scores. Below is an example:

James, 0.974
Harry, 0.971
Ben, 0.968
Tom, 0.965
George, 0.964

For the sake of simplicity, I'd just like to select 2 scores at random to start with. See below:

James, 0.974
Harry, 0.971 <---
Ben, 0.968
Tom, 0.965 <---
George, 0.964

The end result would then be (Harry and Tom):

Average = 0.968

Can anyone help? I've been using 'split', 'import random' etc. But I'm not great at putting these all together. This is embarrassing, but here's what I've got so far...

import random

stroke = random.choice(open('stroke.txt').readlines()) 
for x in stroke:
    name, score = stroke.split(',')
    score = int(score)
    stroke.append((name, score))
print(stroke)
random python
3 Answers

Try with this (explanation on the code):

import random

# read the file in lines
with open('file.txt','r') as f:
    lines = f.read().splitlines()

# split in ',' and get the scores as float numbers 
scores = [ float(i.split(',')[1]) for i in lines]

# get two random numbers
rs = random.sample(scores, 2)

# compute the average
avg = sum(rs)/len(rs)
print avg

Now if you wanted to modify your code you could do it like this:

import random

# pick two instead of one
stroke = random.sample(open('file.txt').readlines(),2) 

scores = []
for x in stroke:
    # split item of list not the list itself
    name, score = x.split(',')
    # store the two scores on the scores list
    scores.append(float(score))

print (scores[0]+scores[1])/2

As @MadPhysicist proposed in the comments, instead of doing (scores[0]+scores[1])/2 a more general way would be sum(scores)/len(scores) since this would work even for more than just two scores.

user_66713420

Assuming that the scores.txt file is formatted like so:

James, 0.974
Harry, 0.971
Ben, 0.968
Tom, 0.965
George, 0.964

Then this should do the trick:

import random

scores = open('scores.txt','r').read()
scores = scores.split('\n')

for i in range(len(scores)):
    scores[i] = scores[i].split(', ')
    scores[i][1] = float(scores[i][1]) * 1000

def rand_avg_scores(scorelist):
    score1 = scorelist.pop(random.randint(0,len(scorelist)-1))
    score2 = scorelist.pop(random.randint(0,len(scorelist)-1))

    finalscore = (score1[1] + score2[1])/2000

    return score1[0], score2[0], finalscore

print(rand_avg_scores(scores))

I added the * 1000 and /2000 bit to account for floating point errors. If the scores have more significant digits, add more zeroes accordingly.

user_77661310

Passing as string, but you can change it from file

import random

scoresString = '''
James, 0.974

Harry, 0.971

Ben, 0.968

Tom, 0.965

George, 0.964
'''

# How much randoms
randomCount = 2

# Get lines of the pure string
linesPure = scoresString.split("\n")

# Get lines that have content
rowsContent = [line for line in linesPure if(line.strip())]

# Get random lines
chosenRows = random.sample(rowsContent, randomCount)

# Sum of chosen
sum = 0

for crow in chosenRows:
    sum += float(crow.split(",")[1].strip())

# Calculate average
average = sum / len(chosenRows)

print("Average: %0.3f" % average)
user_81907390
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