how to delete a column in a python csv file

Question

How do I delete a column from a csv file? example:

nome;nota;idade
joao;10;12
maria;8;13
jose;6;8

to look like this:

nome;idade
joao;12
maria;13
jose;8

and how do I place a new column from that file to another file?

I’m still learning programming excuse if it’s something very simple for the forum

Answer 1

In Python there is the native module csv to work with CSV files. This defines the classes csv.DictReader and csv.DictWriter that facilitate working with the named data.

Take an example:

import csv

with open('original.csv') as stream, \
    open('resultado.csv', 'w') as output:

    reader = csv.DictReader(stream, delimiter=';')
    writer = csv.DictWriter(output, delimiter=';', fieldnames=['nome', 'idade'])

    writer.writeheader()

    for row in reader:
        del row['nota']
        writer.writerow(row)

With contextual managers the two files are opened, the original and the one that will be generated. The object is defined reader which will be responsible for reading the input file and generating a dictionary for each line. The object writer will be responsible for writing the new dictionary in the output file. You scroll through the input file, delete the desired column and write it to the output file.

You can easily abstract this to a function, which takes as a parameter the name of the column you want to remove, as well as fetch the columns from the original file from the reader, this way you create a more versatile solution that will work for different files, with different columns, but this I leave for you to do alone :D

Answer 2

The simplest way to work with csv is by using Pandas. Take a look at this tutorial https://medium.com/data-hackers/uma-introdução-simples-ao-pandas-1e15eea37fa1

The code:

import pandas as pd

pd.read_csv('csv.csv', sep=';')\
    .drop(columns=['nota'])\
    .to_csv('csv_sem_nota.csv', sep=';', index=False)