[Python-Dev] re: list comprehension / pop quiz
Tue, 11 Jul 2000 12:40:22 -0700 (PDT)
On Tue, 11 Jul 2000, Greg Wilson wrote:
> for x in [10, 20, 30]; y in [1, 2]:
> print x+y
> (A) 'x' and 'y' move forward at the same rate:
> (B) 'y' goes through the second list once for each value of 'x':
> (C) an error message because the two lists are not the same length?
> *Everyone* voted (B).
Okay, i just thought of another answer to this.
Scream at me if you find this hideous.
for x in [10, 20, 30] while y in [1, 2]:
My previous message proposed colons to separate the clauses of
a list comprehension, which i now realize makes dict comprehensions
impossible (or at least a little strange-looking). If we use "while",
the lack of semicolons means that we can do parallel loops in
list-comps without colons, which in turn enables dict-comps.
<ducking for cover>