python - 从 .txt 文件中选择随机分数并找到它们的平均值 (Python)

Question

我一直在尝试从 .txt 文件中随机选择分数，然后找出这些随机选择的分数的平均值。下面是一个例子:

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

为了简单起见，我只想随机选择 2 个分数作为开始。见下文:

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

最终结果将是(哈利和汤姆):

平均值 = 0.968

有人可以帮忙吗？我一直在使用“拆分”、“随机导入”等。但我不太擅长将它们放在一起。这很尴尬，但这是我到目前为止所得到的...

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)

Answer 1

试试这个(代码解释):

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

现在如果你想修改你的代码，你可以这样做:

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

正如@MadPhysicist 在评论中提出的，不是做 (scores[0]+scores[1])/2 更通用的方法是 sum(scores)/len(分数)，因为这甚至适用于不止两个分数。