在Python中修改和重写.csv文件

Question

I am trying to read information from a .csv file, change a particular row, then rewrite the file. My code is as follows:

import csv

forename=input("Forename:")
surname=input("Surname:")
percentage=("Percentage number:")

file=open("file1.csv", "r")
read=csv.reader(file)

sort=sorted(read, key=operator.itemgetter(0))

data = [(forename, surname, percentage, "0", "0")]


for line in sort:
    if forename == line[0] and surname == line[1]:
        condition = True
        if line[3] == "0":
            line[3] = score
        elif line [4] == "0":
            line[4] = score
        else:
            line[4] = line[3]
            line[3] = line[2]
            line[2] = score


if condition == False:
    sort.append(data)

file.close()


file=open("file1.csv", "w")
writer=csv.writer(file)

writer.writerows(sort)

file.close()

However, when I try to write to the file, all of the data goes into the first column, and is in the list format (["forename","surname","percentage"]).

This happens even if there is already a record with the same forename and surname (rather than changing the record, then rewriting the file), suggesting that the check isn't working either.

file.csv has the following content (it is made to store the last three percentages):

Cara,Day,80,30,40
Eliza,Fyles,60,37,90
Madeliene,Naylor,30,60,60
George,Hughes,34,0,0
Alice,Berger, 23,38,0
Isaac,James,50,60,85
Kyle,Lyons,22,70,35

What is the issue?

Answer 1

您需要sort.extend(data)而不是append – inspectorG4dget

Answer 2

First, your filter is not working because you are not actually modifying the fields in the "sort" object. Try a loop like this:

for line_num in range(len(sort)):
    if forename == sort[line_num][0] and surname == sort[line_num][1]:
        condition = True
        if sort[line_num][3] == "0":
            sort[line_num][3] = percentage
        elif line [4] == "0":
            sort[line_num][4] = percentage
        else:
            sort[line_num][4] = sort[line_num][3]
            sort[line_num][3] = sort[line_num][2]
            sort[line_num][2] = percentage

alternatively:

new = []
for line in sort:
    if forename == line[0] and surname == line[1]:
        condition = True
        if line[3] == "0":
            line[3] = percentage
        elif line [4] == "0":
            line[4] = percentage
        else:
            line[4] = line[3]
            line[3] = line[2]
            line[2] = percentage
    new.append(line)

if condition == False:
    sort.append(data)
else:
    sort = new

Also, I think you may have to set your variable "data" as a list instead of a tuple:

data = [forename, surname, percentage, "0", "0"]

Answer 3

data should be a list and not a list with a tuple inside.

Like this, ['Madeliene', 'Naylor', '30', '60', '60'] and not this, [('John', 'BAtman', 75, '0', '0')] .

Not knowing what each step of the code is doing will probably lead to messy situations. I'd suggest you fix how data is constructed than change how you add a list to sort .

In [1597]: sort.append(data)

In [1598]: sort
Out[1598]: 
[['Alice', 'Berger', ' 23', '38', '0'],
 ['Cara', 'Day', '80', '30', '40'],
 ['Eliza', 'Fyles', '60', '37', '90'],
 ['George', 'Hughes', '34', '0', '0'],
 ['Isaac', 'James', '50', '60', '85'],
 ['Kyle', 'Lyons', '22', '70', '35'],
 ['Madeliene', 'Naylor', '30', '60', '60'],
 ['John', 'BAtman', 75, '0', '0']]