[Tutor] /tutorial/controlflow.html "break statement"

[Pierre-Michel Averseng]

Hello,

what do you think about the results given by IDLE3 with a script studied 
recently in T. Digest Vol 117, issue 70 & seq. ?

I'm working with Linux (Debian family => i.e Linux Mint LMDE :    
[please, could you excuse my poor English... ?  Thanks !  ;^))   ]
> Linux hojulien 3.10-2-486 #1 Debian 3.10.5-1 (2013-08-07) i686 GNU/Linux
> Python 3.3.2+ (default, Aug  4 2013, 17:23:22)
> [GCC 4.8.1] on linux
The script studied was :

for n in range(2, 10):
     for x in range(2, n):
         if n % x == 0:
             print(n, 'equals', x, '*', n//x)
             break
     else:
         print(n, 'is a prime number')

Here is the result given in IDLE3 on my Presario CQ61:

 >>> for n in range(2,10):
     for x in range(2, n):
         if n % x == 0:
             print(n, '=',x,'*',n//x)
             break
         else:
             # loop fell through without finding a factor
             print(n, 'is a prime number')


3 is a prime number
4 = 2 * 2
5 is a prime number
5 is a prime number
5 is a prime number
6 = 2 * 3
7 is a prime number
7 is a prime number
7 is a prime number
7 is a prime number
7 is a prime number
8 = 2 * 4
9 is a prime number
9 = 3 * 3

         I found this script at : 
http://docs.python.org/3/tutorial/controlflow.html#break-and-continue-statements-and-else-clauses-on-loops

>
>     4.4. break
>     <http://docs.python.org/3/reference/simple_stmts.html#break> and
>     continue
>     <http://docs.python.org/3/reference/simple_stmts.html#continue>
>     Statements, and else
>     <http://docs.python.org/3/reference/compound_stmts.html#else>
>     Clauses on Loops
>
> The break <http://docs.python.org/3/reference/simple_stmts.html#break> 
> statement, like in C, breaks out of the smallest enclosing for 
> <http://docs.python.org/3/reference/compound_stmts.html#for> or while 
> <http://docs.python.org/3/reference/compound_stmts.html#while> loop.
>
> Loop statements may have an else clause; it is executed when the loop 
> terminates through exhaustion of the list (with for 
> <http://docs.python.org/3/reference/compound_stmts.html#for>) or when 
> the condition becomes false (with while 
> <http://docs.python.org/3/reference/compound_stmts.html#while>), but 
> not when the loop is terminated by a break 
> <http://docs.python.org/3/reference/simple_stmts.html#break> 
> statement. This is exemplified by the following loop, which searches 
> for prime numbers:
>
> >>>
> >>>  for  n  in  range(2,  10):
> ...     for  x  in  range(2,  n):
> ...         if  n  %  x  ==  0:
> ...             print(n,  'equals',  x,  '*',  n//x)
> ...             break
> ...     else:
> ...         # loop fell through without finding a factor
> ...         print(n,  'is a prime number')
> ...
> 2 is a prime number
> 3 is a prime number
> 4 equals 2 * 2
> 5 is a....
Surprising !  isn't it ?

Best regards

Pierre