Python，分隔符 csv ';'

Question

It is a simple task to change two columns in.csv file. I use this code:

inn = open('tk.csv', 'w')

import csv

with open('input_2.csv') as File:
     reader = csv.reader(File, delimiter=';')


    for row in reader:
        a = row[0]
        b = row[1]
        a, b = b, a
        print(a,b, file=inn)

And it gives me the mane and value in the same column, separated by a blank space. I know, that in answer there should be delimiter ";" as in the input.csv to separate the name and value on 2 different columns. What should I do?

Answer 1

print("%s,%s"%(a, b), file=inn)
# delimiter is comma above you can change it to whatever you want.

Answer 2

If you want ; as a delimiter in your output, you should write one. The delimiter you use is only relevant for the input.

You can

• either use print("%s;%s" % (a, b), file=inn) for outputting the delimiter,
• or you can instruct print() to produce the correct delimiter ( print(a, b, sep=';', file=inn) ),
• or you can use csv.writer() , which is the recommended way.

Answer 3

You should use csv.writer for writing to csv like that:

import csv

with open('tk.csv', 'w') as output_file:
    writer = csv.writer(output_file, delimiter=';')
    with open('input_2.csv') as input_file:
        reader = csv.reader(input_file, delimiter=';')
        for row in reader:
            a = row[0]
            b = row[1]
            a, b = b, a
            writer.writerow([a, b])