我需要知道如何根据具有多个分数的学生的平均分数对 python 上的字典进行排序？

Question

我的 class 中有很多参加测验的学生的名字。我拿了不止一个，我想用 python 算出平均值。我将分数保存在一个文本文件中，但我不确定如何对其进行编程，所以它会根据总分数除以他们参加考试的次数来对它进行排序。我正在使用 python 3.4.1.

the text file looks like this : 
zor:10
zor:21
bob:30
qwerty:46

我试着按这个排序：

 if schClass == '2':
     schClass = open("scores2.txt", 'r')
     li = open("scores2.txt", 'r')
     data = li.read().splitlines()
     for li in data:
        name = li.split(":")[0]
        score = li.split(":")[1]
        if name not in diction1:
            diction1[name] = score
        elif name in diction1  :
            diction1[name] = (score) + (diction1[name])
            for name in diction1:
                diction1[name] = int(diction1[name])/3

Answer 1

您可以使您的词典具有以下结构：

diction1 = {'zor': [10, 21,], 'bob': [30]}

然后创建一个新的字典来存储名字，平均分：

averages_dct = {'zor': 15.5, }

您的代码应如下所示：

diction1 = {'john': [10, 20], 'mary': [12,], 'chris': [10, 20]}

# Contains names as keys and average as values.
averages_dct = {}

for name in diction1:
    student_average = sum(diction1[name]) / len(diction1[name])

    # Store the value:
    averages_dct.update({name: student_average})


# Dict containing averages as keys and names as values
# (inserting averages first)
reversed_dct = {averages_dct[k]: [] for k in averages_dct}

# (matching names)
for average in reversed_dct:
    for name in averages_dct:
        if average == averages_dct[name]:

            # Adds name of student if he has this average
            reversed_dct[average].append(name)

# Prints the results from highest to lowest.
for av in sorted(reversed_dct, reverse=True):
    print('average: %s, students: %s' % (av, reversed_dct[av]))

Answer 2

这对你有帮助吗？

def dataload():
#This is just to load your data into a custom dictionary, for simplicity
#i wrote example data into a string, you can use your I/O logic 
    test="zor:10\n\
zor:21\n\
bob:30\n\
qwerty:46\n\
zor:24"
    dictionary = {}
    d = test.splitlines()
    for i in d:
        values = i.split(':')
        name  = values[0]
        score = float(values[1])
        if name not in dictionary:
            dictionary[name] = [score]
        else:
            l = dictionary[name]
            l.append(score)            
            dictionary[name] = l
    return dictionary


def printdictionary(d):
#This is shows the content of your custom dictionary
    for item in d.keys():
        l = d[item]
        avg = 0
        for exam in l:
            avg = avg + exam
        avg = avg / len(l)
        print(item," => ", d[item]," => ", avg)

dictionary = dataload()
printdictionary(dictionary)    

# output:
#bob  =>  [30.0]  =>  30.0
#zor  =>  [10.0, 21.0, 24.0]  =>  18.333333333333332
#qwerty  =>  [46.0]  =>  46.0

此代码背后的想法如下：在数据加载方法中 python 从文本文件（字符串或其他地方）读取考试并将它们放入字典中，其中值是考试评估列表。而在 printdictionary 方法中，计算平均分数并将结果显示给用户。

我需要知道如何根据具有多个分数的学生的平均分数对 python 上的字典进行排序？

I need to know how to sort my dictionary on python by aveage scores with students with multi-ple scores?

python

sorting

dictionary

average