[Tutor] Continue Statement

[Peter Otten]

Alina Campana wrote:

> Hello dear tutorlist,

Welcome!

> I feel terribly ashamed for my bad english...
> Yet I'll try to form my question:
> It is about the continue statement in python.I wrote this code
> i = 0while (i < 10):	if i == 5:		continue	print i	i+=1
> What i expected was an output like12346789
> Instead it seems to freeze after 4. The shell input symbol is blinking.
> 
> I bet this is easy enough for pros but I really got my problem with
> understanding the reason why. Okay thank you people, I go now learn better
> english ^^

As long as we can understand you at all a few quirks in your English don't 
matter. Quite a few of as aren't native speakers either.

What does matter is how you format your post -- use text-only if possible at 
all. Anyway, I'm guessing that your code originally looked like this:

i = 0
while (i < 10):	
    if i == 5:		
        continue	
    print i	
    i+=1

Look at the while loop closely -- for 0, 1, 2, 3, and 4 it does not enter 
the if suite. But with i == 5 it executes the continue statement, i. e. it 
goes right back to the while-test. Both `print i` and `i += 1` are skipped, 
i stays at the value 5 forever. 

What you want is to skip the print, but not the increment, and there is no 
straight-forward way to do that using continue and a while loop. But how 
about using for?

for i in range(10):
    if i == 5:
        continue
    print i

In fact I would write it without continue:

for i in range(10):
    if i != 5:
        print i

Now a variant with while (not recommended), just to show how you could skip 
part of the code using continue:

i = 0
while i < 10:
    k = i
    i += 1
    if k == 5:
        continue
    print k

But even that would look better without continue:

i = 0
while i < 10:
    if i != 5:
        print i
    i += 1