I'm trying to write a list of strings like below to a file separated by the given delimiter.

res = [u'123', u'hello world']

When I try splitting by TAB like below it gives me the correctly formatted string.

writer = csv.writer(sys.stdout, delimiter="\t")
writer.writerow(res)

gives --> 123   hello world

But when I try to split by space using delimiter=" ", it gives me the space but with quotation marks like below.

123 "hello world"

How do I remove quotation marks. So that when I use space as the delimiter I should get 123 hello world.

EIDT: when I try using the escapechar it doesn't make any double quotes. But everywhere in my testdata it appears a space, it makes it double.

Quoting behavior is controlled by the various quoting arguments provided to the writer (or set on the Dialect object if you prefer to do things that way). The default setting is QUOTE_MINIMAL, which will not produce the behavior you're describing unless a value contains your delimiter character, quote character, or line terminator character. Doublecheck your test data - [u'123', u'hello'] won't produce what you describe, but [u'123', u' hello'] would.

You can specify QUOTE_NONE if you're sure that's the behavior you want, in which case it'll either try to escape instances of your delimiter character if you set an escape character, or raise an exception if you don't.