从文本文件读取时计算学生平均分数的语法错误

Question

f = open('studMarks.txt', 'r')
marks = 0
# Sort out names, split the words then sort which order
    for line in f:
    words = line.split()
    fname = words[0]
    lname = words[1]
    print(f"{lname},{fname}")
f.close()

f = open('studMarks.txt', 'r')
sum = 0
count = 0
for line in f:
    count += 1
    sum += float(line.split()[2])
    n = []
average = sum/count

print(f"{average}")

当使用 for 循环时，它似乎显示 64.3 的值，我认为这是整个学生列表的总分和所有分数的平均值。

我需要生成在同一行显示学生姓名和平均分的输出。我可以为名字做，但我不能为平均值做，因为我不断出错。不知道输入什么

Answer 1

这是一个有趣的问题。据我了解，您有一个如下所示的文本文件： Johnny Ly 90 100 Adam Best 80 30 Tim Smith 10 20 在名为 studentMarks2.txt 的文件中并想要这样的输出： Johnny_Ly 95.0 Adam_Best 55.0 Tim_Smith 15.0 如果这是真的，那么可以使用没有 pandas 或 csv 的代码来完成尽管这些会使这变得容易得多。

fileContents = []

with open('studMarks2.txt','r') as f:
    fileContents = f.read().split()
    

students = dict()

names = []
for content in fileContents:
    if content.isnumeric():
        studentKey = '_'.join(names)
        currentScore = students.get(studentKey,[])        
        newScore = currentScore + [float(content)]
        students.update({studentKey:newScore})        
    else:
        if len(names) == 2:
            names.clear()
            names.append(content)
        else:
            names.append(content)
            
for student,scores in students.items():
    avg = sum(scores)/len(scores)
    print(student,avg,end=' ')

崩溃了这部分阅读内容并在白色上拆分space

fileContents = []    
    with open('studMarks2.txt','r') as f:
        fileContents = f.read().split()

这部分然后遍历内容将名称作为键存储在字典中并将分数放入列表中

students = dict()        
    names = []
    for content in fileContents:
        if content.isnumeric():
            studentKey = '_'.join(names)
            currentScore = students.get(studentKey,[])        
            newScore = currentScore + [float(content)]
            students.update({studentKey:newScore})        
        else:
            if len(names) == 2:
                names.clear()
                names.append(content)
            else:
                names.append(content)

最后它遍历字典并在一行上输出平均值

for student,scores in students.items():
    avg = sum(scores)/len(scores)
    print(student,avg,end=' ')

Answer 2

下面是完整的解决方案。 with open 行是上下文管理器，可确保文件在您退出该块后立即关闭。您应该习惯使用这种风格，因为这是安全的做法 I/O。其余的只是沼泽标准 Python.

marks=dict()
with open('studMarks.txt', 'r') as f:
    for line in f:
        words = line.split()
        fname = words[0]
        lname = words[1]
        score = int(words[2])
        key = f'{fname} {lname}'
        count_key = f'{fname} {lname}_count'
        latest_score = score + (marks.get(key)[0] if marks.get(key) else 0)
        latest_count = 1 + (marks.get(key)[1] if marks.get(key) else 0)
        marks[key] = (latest_score, latest_count )
for name, value in marks.items():
    print(f'{name} : {value[0]/value[1]}')

从文本文件读取时计算学生平均分数的语法错误

Syntax error calculating the average of student marks while reading from a text file

python

average