csv - 在python中格式化CSV文件中的数据(计算平均值)

Question

import csv
with open('Class1scores.csv') as inf:
    for line in inf:
        parts = line.split() 
        if len(parts) > 1:   
            print (parts[4])   


f = open('Class1scores.csv')
csv_f = csv.reader(f)
newlist = []
for row in csv_f:

    row[1] = int(row[1])
    row[2] = int(row[2])
    row[3] = int(row[3])

    maximum = max(row[1:3])
    row.append(maximum)
    average = round(sum(row[1:3])/3)
    row.append(average)
    newlist.append(row[0:4])

averageScore = [[x[3], x[0]] for x in newlist]
print('\nStudents Average Scores From Highest to Lowest\n')

此处的代码旨在读取 CSV 文件，在前三行(第 0 行是用户名)中，它应将所有三个分数相加并除以三，但它不会计算出正确的平均值，它只是从最后一列中获取分数。

Answer 1

基本上您需要每一行的统计信息。一般来说，你应该这样做:

import csv

with open('data.csv', 'r') as f:
    rows = csv.reader(f)
    for row in rows:
        name = row[0]
        scores = row[1:]

        # calculate statistics of scores
        attributes = {
           'NAME': name,
           'MAX' : max(scores),
           'MIN' : min(scores),
           'AVE' : 1.0 * sum(scores) / len(scores)
        }

        output_mesg ="name: {NAME:s} \t high: {MAX:d} \t low: {MIN:d} \t ave: {AVE:f}"
        print(output_mesg.format(**attributes))

尽量不要考虑在本地做特定的事情是否效率低下。一个好的 Pythonic 脚本应该对每个人都尽可能的可读。

在您的代码中，我发现了两个错误:

1. 追加到 row 不会改变任何内容，因为 row 是 for 循环中的局部变量，会被垃圾回收。

2. row[1:3] 只给出了第二个和第三个元素。 row[1:4] 提供您想要的内容，row[1:] 也是如此。 Python 中的索引通常是最终独占的。

还有一些问题需要你思考:

If I can open the file in Excel and it's not that big, why not just do it in Excel? Can I make use of all the tools I have to get work done as soon as possible with least effort? Can I get done with this task in 30 seconds?