How to write to consecutive CSV columns in Python

Question

I am writing data from a list to a csv file like this:

def writeToCsv(list, max):
    writer = csv.writer(open('file.csv', 'wb'), delimiter=' ')
    for x in range(0,max):
        writer.writerow(list[x]['year'])

This fills the first column with the years which is great. Now I want to fill the next column with the 'name' in the list. How can I run the above code again but have it fill the next column instead of writing over the first column with the 'name'?

When using the `csv` module, you should structure your code so you write one *row* at a time, not one column. That's why the method is called `writerow`. — BrenBarn, Jan 25 '15 at 23:03

score 1 · Accepted Answer · edited May 23 '17 at 11:49

1

Just give a list to writerow:

def writeToCsv(list, max):
    writer = csv.writer(open('file.csv', 'wb'), delimiter=' ')
    for x in range(0,max):
        writer.writerow([list[x]['year'], list[x]['name']])

Notice you can do this:

def writeToCsv(lst, limit):
    # use a context manager to close the file for you when you're done
    with open('file.csv', 'wb') as f:
        writer = csv.writer(f, delimiter=' ')
        # takes the first `max` dictionaries from the list
        for item in lst[:limit]:
            writer.writerow([item['year'], item['name']])

This is using slicing and the with context manager.

note: I've changed the names of the function arguments so that you don't shdow the built-in functions list and max. (thanks @Padraic Cunningham)

edited May 23 '17 at 11:49

Community

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answered Jan 25 '15 at 23:02

Reut Sharabani

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might be worth mentioning and changing the numerous builtin names that are being shadowed – Padraic Cunningham Jan 25 '15 at 23:07
This puts both 'year' and 'name' into the same first column – Cybernetic Jan 25 '15 at 23:20
Just had to change the delimiter to a comma. Thank you :) – Cybernetic Jan 25 '15 at 23:23

How to write to consecutive CSV columns in Python

1 Answers1