white space in expressions and argument lists

[John Salerno]

A minor concern, but I'm curious if there is any kind of best practice 
for using whitespace within expressions and argument lists in the Python 
world. For example:

1 + 2  or   1+2

func(1,2) or func(1, 2)

To me, the space makes it nicer and more readable, but I was surprised 
to read in Guido's blog that he thinks 1+2 should be the normal way to 
write it. What does everyone else think?