I know I can write a CSV file with something like:

with open('some.csv', 'w', newline="") as f:

How would I instead write that output to stdout?

sys.stdout is a file object corresponding to the program’s standard output. You can use its write() method. Note that it’s probably not necessary to use the with statement, because stdout does not have to be opened or closed.

So, if you need to create a csv.writer object, you can just say:

import sys
spamwriter = csv.writer(sys.stdout)