flow control and nested loops

Fri Sep 25 15:01:47 EDT 2009

In Perl, one can label loops for finer flow control. For example:
X: for my $x (@X) {
 Y: for my $y (@Y) {
 for my $z (@Z) {
 next X if test1($x, $y, $z);
 next Y if test2($x, $y, $z);
 frobnicate($x, $y, $z);
 }
 glortz($x, $y); 
 }
 splat($x); 
}
What's considered "best practice" in the Python world for this sort
of situation? The only approach I can think of requires setting
up indicator variables that must be set and tested individually;
e.g.
for x in X:
 next_X = False
 for y in Y:
 next_Y = False
 for z in Z:
 if test1(x, y, z):
 next_X = True
 break
 if test2(x, y, z):
 next_Y = True
 break
 frobnicate(x, y, z)
 if next_X:
 break
 if next_Y:
 continue
 glortz(x, y) 
 if next_X:
 continue
 splat(x) 
Whereas I find the Perl version reasonably readable, the Python
one I find nearly incomprehensible. In fact, I'm not even sure
that the Python version faithfully replicates what the Perl one is
doing!
Is there a better approach?
TIA!
kynn