How to catch StopIteration?

[Chris]

On Jun 17, 5:50 am, ccy56... at gmail.com wrote:
> I'm writing to see calcuration process.
> And so, I can't catch StopIteration...
>
> What is mistake?
>
> def collatz(n):
>   r=[]
>   while n>1:
>     r.append(n)
>     n = 3*n+1 if n%2 else n/2
>     yield r
>
> for i, x in enumerate(collatz(13)):
>   try:
>     last = x[:i+1]
>     print x[:i+1]
>   except StopIteration:
>     print last.appnd(1)
>
> Output:
> [13]
> [13, 40]
> [13, 40, 20]
> [13, 40, 20, 10]
> [13, 40, 20, 10, 5]
> [13, 40, 20, 10, 5, 16]
> [13, 40, 20, 10, 5, 16, 8]
> [13, 40, 20, 10, 5, 16, 8, 4]
> [13, 40, 20, 10, 5, 16, 8, 4, 2]
> last.appnd(1) <= [13, 40, 20, 10, 5, 16, 8, 4, 2, 1]  # i want this
> list

def collatz(n):
  r=[]
  while n>1:
    r.append(n)
    n = 3*n+1 if n%2 else n/2
    yield r

i = 1
while 1:
    try:
        last = x[:i]
        print x[:i]
        i += 1
    except StopIteration
        last.append(1)
        break

You will have to control the for loop yourself otherwise the
StopIteration is handled for you.