如何将一个CSV文件中的多行和一列复制到另一个CSV Excel中？

Question

I am extremely new to python(coding, for that matter). Could I please get some help as to how can I achieve this. I have gone through numerous threads but nothing helped.

My input file looks like this:

I want my output file to look like this:

Just replication of the first column, twice in the second excel sheet. With a line after every 5 rows.

Answer 1

A .csv file can be opened with a normal text editor, do this and you'll see that the entries for each column are comma-separated (csv = comma separated values). Most likely it's semicolons ; , though.

Since you're new to coding, I recommend trying it manually with a text editor first until you have the desired output, and then try to replicate it with python.

Also, you should post code examples here and ask specific questions about why it doesn't work like you expected it to work.

Answer 2

Below is the solution. Don't forget to configure input/output files and the delimiter:

input_file = 'c:\Temp\input.csv'
output_file = 'c:\Temp\output.csv'
delimiter = ';'

i = 0
output_data = ''
with open(input_file) as f:
    for line in f:
        i += 1
        output_data += line.strip() + delimiter + line
        if i == 5:
            output_data += '\n'
            i = 0

with open(output_file, 'w') as file_:
    file_.write(output_data)

Answer 3

Python has a csv module for doing this. It is able to automatically read each row into a list of columns. It is then possible to simply take the first element and replicate it into the second column in an output file.

import csv

with open('input.csv', 'rb') as f_input:
    csv_input = csv.reader(f_input)
    input_rows = list(csv_input)

with open('output.csv', 'wb') as f_output:
    csv_output = csv.writer(f_output)

    for line, row in enumerate(input_rows, start=1):
        csv_output.writerow([row[0], row[0]])

        if line % 5 == 0:
            csv_output.writerow([])

Note, it is not advisable to write the updated data directly over the input file as if there was a problem you would lose your original file.

If your input file has multiple columns, this script will remove them and simple duplicate the first column.

By default, the csv format separates each column using a comma, this can be modified by specifying a desired delimiter as follows:

csv_output = csv.writer(f_output, delimiter=';')