1.5.2 for: else:

[Thomas Wouters]

On Tue, Jul 27, 1999 at 04:15:44PM +0400, Oleg Broytmann wrote:

>    The following program:

> ----------
> for a in ['a', 12]:
>    print a
> else:
>    print "Empty!"
> ----------

http://www.python.org/doc/current/tut/node6.html#SECTION006200000000000000000

[..]
4.4 break and continue Statements, and else Clauses on Loops 

Loop statements may have an else clause; it is executed when the loop
terminates through exhaustion of the list (with for) or when the condition
becomes false (with while), but not when the loop is terminated by a break
statement. 
[..]

So, 

>>> def do_a(list):      
...     for a in list:
...         if not a:
...             break
...         print a
...     else:
...         print "No FALSE items in list!"
...

>>> do_a(['a', 12])
a
12
No FALSE items in list!

>>> do_a(['a', 12, []])
a
12

>>> do_a(['a', 12, 0])
a
12

Else clauses get executed on normal loop exit, even if the loop was 'empty'.
It does not get executed when you 'break' out of a loop.

-- 
Thomas Wouters <thomas at xs4all.net>

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