Is there any way to create column header in csv file instead of row headers using python

Question

I am using the following way to create the row headers:

header_names = ["Test Number", "result", "output_value","duration_of_test"]
csvwriter = csv.DictWriter(open(out_file, 'wb'), delimiter=',', fieldnames=header_names)
csvwriter.writeheader()

In the above code, when we are creating the header, by default it creates row header. But is there any way to create column header i.e., first column is header column and rest of the columns are test results.

http://stackoverflow.com/questions/4869189/how-to-pivot-data-in-a-csv-file — DevLounge, Jan 20 '16 at 20:11
Thanks for pointing the example. Its post processing of existing data. But I require while creating the file itself. — nnvgps, Jan 20 '16 at 23:02

score 1 · Accepted Answer · answered Jan 21 '16 at 08:42

In order to do what you need, you will need to have all of your data ready to be written. When writing to a file, it will always be a row at a time, it is not possible to write a column at a time. As such you would need to take the following kind of approach:

import csv

out_file = 'output.csv'
header_names = ["Test Number", "result", "output_value","duration_of_test"]

data = [[1, 5, 10, 20], [2, 6, 20, 25], [3, 7, 8, 15]]
data.insert(0, header_names)

with open(out_file, 'wb') as f_output:
    csv_output = csv.writer(f_output)
    csv_output.writerows(zip(*data))

Where data holds all of your test results. First the header_names are added to the start of the data list. Then a trick using Python's zip function has the effect of transposing your data into the format you were looking for.

This would give you the following kind of output:

Test Number,1,2,3
result,5,6,7
output_value,10,20,8
duration_of_test,20,25,15

Is there any way to create column header in csv file instead of row headers using python

1 Answers1