OverWrite an existing list in CSV files Python

Question

I have a csv files with player attributes:

['Peter Regin', '2', 'DAN', 'N', '1987', '6', '6', '199', '74', '2', '608000', '', '77', '52', '74', '72', '58', '72', '71', '72', '70', '72', '74', '68', '74', '41', '40', '51']
['Andrej Sekera', '8', 'SVK', 'N', '1987', '6', '6', '198', '72', '3', '1323000', '', '65', '39', '89', '78', '75', '70', '72', '56', '53', '56', '57', '72', '57', '59', '70', '51']

For example, I want to check if a player is a CENTER ('2' in position 1 in my list) and after I want to modify the 12 element (which is '77' for Peter Regin)

How can I do that using the CSV module ?

import csv


class ManipulationFichier:


    def __init__(self, fichier):
        self.fichier = fichier

    def read(self):

        with open(self.fichier) as f:
            reader = csv.reader(f)

            for row  in reader:
                print(row)


    def write(self):

        with open(self.fichier) as f:
            writer = csv.writer(f)

            for row in f:
                if row[1] == 2: 
                    writer.writerows(row[1] for row in f)

Which do nothing important..

Thanks,

Can you show us the code you have so far?

John La Rooy
– John La Rooy

2013-05-13 23:59:17 +00:00
Commented May 13, 2013 at 23:59 — John La Rooy
– John La Rooy, Commented May 13, 2013 at 23:59

9000 · Accepted Answer · 2013-05-14 00:02:42Z

2

In general, CSV files cannot be reliably modified in-place.

Read the entire file into memory (usually a list of lists, as in your example), modify the data, then write the entire file back.

Unless your file is really huge, and you do this really often, the performance hit will be negligible.

answered May 14, 2013 at 0:02

9000

41k9 gold badges70 silver badges108 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Antonio Banderas Over a year ago

What is the most effective way. So I should use the mmap module ? Or write in a list ? using the reader and append ?

9000 Over a year ago

Forget efficiency until you attain correct functioning. Do the simplest thing possible. I bet the bottlenecks of your program are going to be elsewhere :)

Collectives™ on Stack Overflow

OverWrite an existing list in CSV files Python

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related