CODEWITHSUNDEEP
pythonpython-3.xcsv
marcorivera8
marcorivera8

Reputation: 257

Add columns to existing CSV file

I am trying to add new columns to an existing csv that already has rows and columns that looks like this: enter image description here

I would like it to append all the new column names to the columns after column 4.

The code I currently have is adding all the new columns to the bottom of the csv:

def extract_data_from_report3():
    with open('OMtest.csv', 'a', newline='') as f_out:
        writer = csv.writer(f_out)
        writer.writerow(
            ['OMGroup:OMRegister', 'OMGroup', 'OMRegister', 'RegisterType', 'Measures', 'Description', 'GeneratedOn'])

Is there any way to do this effectively?

Upvotes: 0

Views: 1805

Answers (1)

Nikaido
Nikaido

Reputation: 4629

You can use the pandas lib, without iterating through the values. Here an example

new_header = ['OMGroup:OMRegister', 'OMGroup', 'OMRegister', 'RegisterType', 'Measures', 'Description', 'GeneratedOn']
# Import pandas package  
import pandas as pd 

my_df = pd.read_csv(path_to_csv)
for column_name in new_header:
    new_column = [ ... your values ...] #should be a list of your dataframe size
    my_df[column_name] = new_column

keep in mind that the new column should have the same size of the number of rows of your table to work

If you need only to add the new columns without values, you can do as such:

for column_name in new_header:
    new_column = ["" for i in range(len(mydf.index))] #should be a list of dataframe size
    my_df[column_name] = new_column

Then you can write back the csv in this way:

my_df.to_csv(path_to_csv)

Here details on the read_csv method

Here details on the to_csv method

Upvotes: 2

Related Questions