Question

我想从文本文件中对内容进行排序。我已经按字母顺序（名称）对它们进行了排序。我得到的问题是，当我尝试按升序或降序对分数进行排序时，程序不会将10识别为10而是将其识别为1.我已附加了我的代码和文本文件。

Python 3.4 代码：

import csv
import operator

quizGrades= open('Quiz-1.txt' , 'r')


def menu():
    print('To Check The scores by ALPHABETICLE Order  [1]')
    print('To Check The Scores In ASCENDING Order   [2]')
    print('To check the AVERAGE Scores of Each Student  [3]')
    choice=int(input(':'))
    if choice==1:
        alpha()

    elif choice==2:
        ascend()

def alpha():
    quizGrades = open('Quiz-1.txt' , 'r')

    grades = csv.reader(quizGrades, delimiter =',')

    sortedGrades = sorted(grades, reverse= False, key=operator.itemgetter(1))

    for eachline in sortedGrades:
        print()
        print (eachline)
        quizGrades.close()

def ascend():
        quizGrades = open('Quiz-1.txt' , 'r')

        grades = csv.reader(quizGrades, delimiter =',')

        sortedGrades = sorted(grades, reverse= False, key=operator.itemgetter(4))

        for eachline in sortedGrades:
            print()
            print (eachline)
            quizGrades.close()


menu()

文本文件

Name:,Aum Patel,Class:1,Score:,10,/10
Name:,Lolly Pop,Class:1,Score:,9,/10
Name:,Kimjon Un,Class:1,Score:,5,/10
Name:,Gurpreet Perv,Class:1,Score:,7,/10
Name:,Aum Patel,Class:1,Score:,8,/10
Name:,Amanjeet Singh,Class:1,Score:,2,/10
Name:,Kimjon Un,Class:1,Score:,1,/10
Name:,Aum Patel,Class:1,Score:,10,/10
Name:,Chong Singh,Class:1,Score:,1,/10
Name:,Amanjeet Singh,Class:1,Score:,7,/10
Name:,Akky Chandrakumar,Class:1,Score:,8,/10

Answer 1

您需要将从txt文件读取的字符串转换为整数

grades = [int(grade) for grade in grades]

如果你比较字符串，结果将如下

numString = ["1","5000","3","6","30","4","2","200"]
print(sorted(numString))

['1', '2', '200', '3', '30', '4', '5000', '6']

Answer 2

您将数字排序为字符串，而不是数字。您需要更改ascend()功能，如下所示：

def ascend():
        quizGrades = open('Quiz-1.txt' , 'r')

        grades = csv.reader(quizGrades, delimiter =',')

        sortedGrades = sorted(grades, reverse= False, key=lambda x: int(x[4]))

        for eachline in sortedGrades:
            print()
            print (eachline)
            quizGrades.close()

key=lambda x: int(x[4])会将数字转换为排序的整数，而不会更改字符串的输出。

后续评论

我还建议CSV文件的更常见格式为：

"Name","Class","Score","Total Points"
"Aum Patel",1,10,10
...

第一行是标题行，后续行只包含值，因此不需要从文本文件同一行的标签中解析出值。使用此格式，并使用quoting=csv.QUOTE_NONNUMERIC csv.reader()行，您的原始排序可行：

import csv
import operator

with open('Quiz-1.txt', 'r') as f:
    grades = csv.reader(f, delimiter=",", quoting=csv.QUOTE_NONNUMERIC)  # Treat any unquoted values as floats.
    next(grades)  # Skip the header row.
    sorted_grades = sorted(grades, reverse=False, key=operator.itemgetter(2))  # Just changed column.

for row in sorted_grades:
    print(row)

我在python中编写一个程序来对文本文件进行排序

2 个答案:

后续评论