Python: creating a comma separated string from a query

Question

I have a query

 messages = Message.objects.all()

I want to create a Create a comma separated string of all numbers from message.number

This is what I have tried:

number = ""
for obj in messages:
     number = number + "," + obj.number

How can I do this? PS this string can be VERY long over 400,000 numbers!

Are you going to write this back out to a file? – Burhan Khalid Aug 27 '13 at 11:33 — Burhan Khalid, Aug 27 '13 at 11:33

score 8 · Accepted Answer · edited May 23 '17 at 12:03

8

Use join():

",".join(str(msg.number) for msg in Message.objects.all())

Also, since you have a large queryset, consider splitting your results into chunks using a queryset iterator. For more info see:

edited May 23 '17 at 12:03

Community

answered Aug 27 '13 at 11:28

alecxe

1

This won't work if `msg.number` is actually a _number_, better cast it to string first; and you also have extra `( )` in there. – Burhan Khalid Aug 27 '13 at 11:32

score 1 · Answer 2 · answered Aug 27 '13 at 11:28

1

number = ','.join(messages)

answered Aug 27 '13 at 11:28

Sjoerd

2 Answers2