[Tutor] Generator function question?

[Jacob S.]

> import sys
>
> def neverEndingStatus(currentChar_ = '|'):
>    while 1:
>        if currentChar_ == '|':
>            currentChar_ = '\\'
>        elif currentChar_ == '\\':
>            currentChar_ = '-'
>        elif currentChar_ == '-':
>            currentChar_ = '/'
>        elif currentChar_ == '/':
>            currentChar_ = '|'
>        yield currentChar_
>
>
> x = neverEndingStatus()
>
> def Test1():
>    for w in range(1, 100):
>        sys.stderr.write('\b'+x.next())

########################################
>        for z in range(1, 10000):
>            z = z + 1

What on earth is the point of this? Why put a loop in there that does 
nothing?
Are you just trying to take time?
########################################

> def Test2():
>    for y in range(1, 10):
>        sys.stderr.write('\b \nTesting'+str(y)+'\t')
>        Test1()
>
> Test2()

import sys
from itertools import cycle

# nesl = Never ending status list
nesl = ["|","\\","-","/"]

a = cycle(nesl)

## ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ##
## | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ##
## This is just using itertools' cycle to automatically make the iterator 
you were trying for ##

# Now we rewrite your test cases

def Test1():
    sys.stderr.write("\b"+"\b".join(a.next() for x in range(1,100)))
    ## You realize that this will only give you 99 characters, not 100

def Test2():
    for i in range(1,10):  ## You realize again that this only runs 9 
times...
        sys.stderr.write("\b \nTesting %s\t" % y)
        Test1()

Test2()


Well, this is not tested, but it shows that you can use itertools.cycle to 
do what you want.

Also, the test cases are slightly neater (to me) too.

Okay, I'm done
Jacob