Python keywords

[gtb]

Have done some searching but have not found a place where I can look
up python keywords. I was looking at a script that contained the
following line:

assert self.getResponseCode() in (200, 304, 302)

I can infer the usage here but previously I had thought that "in" was
only used with '"for". I looked thru 'the Python Reference Manual and
found "in" is a keyword but in skimming thru I found it only with
"for". The reference manual seems good but seems not to be setup for
searching. Or maybe I just missed something.

Thanks,

gtb