Question

I am using Google App Engine (python), I want my users to be able to download a CSV file generated using some data from the datastore (but I don’t want them to download the whole thing, as I re-order the columns and stuff).

I have to use the csv module, because there can be cells containing commas. But the problem that if I do that I will need to write a file, which is not allowed on Google App Engine

What I currently have is something like this:

    tmp = open("tmp.csv", 'w')
    writer = csv.writer(tmp)
    writer.writerow(["foo", "foo,bar", "bar"])

So I guess what I would want to do is either to handle cells with commas.. or to use the csv module without writing a file as this is not possible with GAE..

Answer 1

I found a way to use the CSV module on GAE! Here it is:

self.response.headers['Content-Type'] = 'application/csv'
writer = csv.writer(self.response.out)

writer.writerow(["foo", "foo,bar", "bar"])

This way you don’t need to write any files