Python: CSV write by column rather than row

Question

I have a python script that generates a bunch of data in a while loop. I need to write this data to a CSV file, so it writes by column rather than row.

For example in loop 1 of my script I generate:

(1, 2, 3, 4) 

I need this to reflect in my csv script like so:

Result_1    1 Result_2    2 Result_3    3 Result_4    4 

On my second loop i generate:

(5, 6, 7, 8) 

I need this to look in my csv file like so:

Result_1    1    5 Result_2    2    6 Result_3    3    7 Result_4    4    8 

and so forth until the while loop finishes. Can anybody help me?

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EDIT

The while loop can last over 100,000 loops

Answer 1

The reason csv doesn't support that is because variable-length lines are not really supported on most filesystems. What you should do instead is collect all the data in lists, then call zip() on them to transpose them after.

>>> l = [('Result_1', 'Result_2', 'Result_3', 'Result_4'), (1, 2, 3, 4), (5, 6, 7, 8)] >>> zip(*l) [('Result_1', 1, 5), ('Result_2', 2, 6), ('Result_3', 3, 7), ('Result_4', 4, 8)] 

Answer 2

wr.writerow(item)  #column by column wr.writerows(item) #row by row 

This is quite simple if your goal is just to write the output column by column.

If your item is a list:

yourList = []  with open('yourNewFileName.csv', 'w', ) as myfile:     wr = csv.writer(myfile, quoting=csv.QUOTE_ALL)     for word in yourList:         wr.writerow([word])