Python：将输出保存到csv文件时出错？

Question

I realized this error only when open with MS Excel but it is just fine when open using Notepad++. The values are not in corresponding columns when I open using Excel. I have this following code which help me to do multiplication only according to value 1 in binary.csv and outputting values excluding all the 0 values in binary.csv. Can anyone help me?

binary.csv

0,1,0,0,1,0,1,0,0
1,0,0,0,0,1,0,1,0
0,0,1,0,1,0,1,0,0

real.csv

0.1,0.2,0.4,0.1,0.5,0.5,0.3,0.6,0.3

Code

import csv

with open('real.csv', 'rb') as csvfile:
    for row in csv.reader(csvfile, delimiter=','):
        reals = row

with open('binary.csv', 'rb') as csvfile:
    pwreader = csv.reader(csvfile, delimiter=',')

    with open('onehothot.csv','wb') as testfile:
        csv_writer=csv.writer(testfile)
        for row in pwreader:
            result = []

            for i,b in enumerate(row):
                if b == '1' :
                    result.append(reals[i])

            c= ",".join(result)
            print(c)
            csv_writer.writerow([c])

Output in csv file open using Notepad++

0.2,0.5,0.3
0.1,0.5,0.6
0.4,0.5,0.3

Desired output in csv file open using MS Excel (in 3 rows and 3 columns filled)

0.2 0.5 0.3
0.1 0.5 0.6
0.4 0.5 0.3 

The actual CSV output file I open using MS Excel is in 3 rows and 1 column filled because '0.2 0.5 0.3' is treated as single entity. Therefore only 3 entities displayed in Excel.

Answer 1

There is no need to try and create each column by joining with , as the csv library will do this for you, instead code it as follows:

import csv

with open('real.csv', 'rb') as csvfile:
    for row in csv.reader(csvfile, delimiter=','):
        reals = row

with open('binary.csv', 'rb') as csvfile:
    pwreader = csv.reader(csvfile, delimiter=',')

    with open('onehothot.csv','wb') as testfile:
        csv_writer=csv.writer(testfile)
        for row in pwreader:
            result = []

            for i,b in enumerate(row):
                if b == '1' :
                    result.append(reals[i])

            csv_writer.writerow(result)