Assignment in a while?

[bill pursell]

none wrote:

> import pgdb;
>
> dbh = pgdb.connect(database = 'test')
> sth = dbh.cursor()
> sth.execute("SELECT * FROM capitals")
> #while 1:
>      #results = sth.fetchone()
>      #if results == None:
>          #break
>      #print results
> while results = sth.fetchone():
>      print results
>
> If I try to run the above code, I get a SyntaxError indicating that I
> can't do an assignment in the while loop.  I found a way around this
> (see the commented out while loop), but it seems hackish.  Assignment
> within a while loop seems like a pretty standard thing, so I'm just
> curious what I'm missing.

A more pythonic way to do that is something like:

for results in sth.fetchall():
    print results

(I'm not familiar with pgdb, but if it's a reasonable module it will
have some function that returns an iterator.)

In the beginning of my python experience, I was a bit irritated at
being unable to assign and check a condition in one statement, but the
irritation really doesn't last very long.  Python has a huge amount of
inherent beauty, and is well worth the time.