[brianmen]

Hi all,

I am wondering if there is a way to exit the while loop before executing all of it...

For example:

stop=0
limit=5
while (stop < limit+1):
    print "one"
    stop=stop+1
    print "two"
    stop=stop+1
    print "three"
    stop=stop+1
    print "four"
    stop=stop+1
    print "five"
    stop=stop+1
    print "six"
    stop=stop+1
    stop=stop+1
    print "getting too close"
    print "gone too far"

gives me an output of:

one
two
three
four
five
six
getting too close
gone too far

How can I exit the while loop EXACTLY when "stop" and "limit" are equivalent in value?

Thanks for your help!

[Eric115]

If you are trying to exit it from with-in your code, then you can use the break like c.user said but if you want to stop the loop externally press ctrl+C and the script should stop. This is usefull to know when you get stuck in a loop.

[Cuzzie]

Quote

How can I exit the while loop EXACTLY when "stop" and "limit" are equivalent in value?

Maybe something like this...

while(stop != limit):
     #Your code

[Motoma]

This is a good question, but it alludes to more complicated issues that depend on the situation you are programming for.

Could you give a real-world example of what you are trying to accomplish?

[brianmen]

Thanks everyone,

Motoma, for a real world example, the only difference between my loop that I posted here and the loop I'm actually using is that some items are being added to a list. So rather than print statements, I'm using the

list.append("")

statement to put some padding into a list. When the condition in the while loop at top becomes false, I want to stop adding "" to my list.

orangcacat, on 30 July 2010 - 02:19 AM, said:

Quote

How can I exit the while loop EXACTLY when "stop" and "limit" are equivalent in value?

Maybe something like this...

while(stop != limit):
     #Your code

Orangecat, that style of while loop is something I tried before my current scenario...

Doing

stop=0
limit=5
while (stop != limit):
    print "one"
    stop=stop+1
    print "two"
    stop=stop+1
    print "three"
    stop=stop+1
    print "four"
    stop=stop+1
    print "five"
    stop=stop+1
    print "six"
    stop=stop+1
    stop=stop+1
    print "getting too close"
    print "gone too far"

actually puts me into an infinite loop.... I feel like I'm missing something important here...

Thanks anyway for trying...

[Motoma]

brianmen, on 30 July 2010 - 10:15 AM, said:

Motoma, for a real world example, the only difference between my loop that I posted here and the loop I'm actually using is that some items are being added to a list. So rather than print statements, I'm using the

list.append("")

statement to put some padding into a list. When the condition in the while loop at top becomes false, I want to stop adding "" to my list.

Individual circumstances lend themselves to individual solutions. For the loop you posted, my solution would be:

limit = 5
lookup = ['one', 'two', 'three', 'four', 'five', 'six']
for i in range(limit):
    print lookup[i]

But surely that's not what you want.

Another way to do this would be:

stop = 0
limit = 5
while stop > limit:
    if stop == 1: print "one"
    elif stop == 2: print "two"
    elif stop == 3: print "three"
    elif stop == 4: print "four"
    elif stop == 5: print "five"
    elif stop == 6: print "six"
    else: pring "Too far!"
    stop += 1

Still another solution would be:

stop=0
limit=5
while true:
    if stop = 0: print "one"
    stop += 1
    if stop > limit: break

    if stop = 0: print "two"
    stop += 1
    if stop > limit: break

    if stop = 0: print "three"
    stop += 1
    if stop > limit: break

    if stop = 0: print "four"
    stop += 1
    if stop > limit: break

    if stop = 0: print "five"
    stop += 1
    if stop > limit: break

    if stop = 0: print "six"
    stop += 1
    if stop > limit: break

In fact, there are a dozen other correct solutions to the problem, the right one to use depends on the actual problem. If you could post the code that you are having problems with, we would be able to guide you better.

Cheers,
Motoma

[brianmen]

Motoma, those are some good solutions. I'll keep them in mind for the future. I was able to get what I needed done by using c.user's code as a model.

i = 0
while i < 10:
  print(i)
  i += 1
  if i == 3:
    break

It's a bit inefficient in practice, but it worked for me.

Thanks to everyone who helped me out. =)