enumerate vs while

[Patrick C]

Sorry for the simplicity of my questions, but is enumerate a way around using while loops

my while loop is this:

x = 1
>>> while x < len(rate):
...     try:
...         growth.append(rate[x])
...         x += 3
...     except IndexError:
...         break
... 

thanks

[bvdet]

Sorry for the simplicity of my questions, but is enumerate a way around using while loops

my while loop is this:

x = 1
>>> while x < len(rate):
...     try:
...         growth.append(rate[x])
...         x += 3
...     except IndexError:
...         break
... 

thanks

Use enumerate() when you need an index number and an item from an iterable:

for i, item in enumerate(rates):
    if not (i-1) % 3:
        growth.append(item)

Another form using range():

for i in range(1, len(rates), 3):
    growth.append(rates[i])

[ghostdog74]

Sorry for the simplicity of my questions, but is enumerate a way around using while loops

my while loop is this:

x = 1
>>> while x < len(rate):
...     try:
...         growth.append(rate[x])
...         x += 3
...     except IndexError:
...         break
... 

thanks

a better way to create a while loop (IMO) is using infinity loop.
eg

while 1:
    #statements...
    if some condition:
        break
    if another condition:
        break
 

this way, you can customize your loop according to different conditions, whereas in your example, you can only exit while loop on x>len(rate).
and as to your question, enumerate() works on iterable objects, ie range(), open files, etc.. see here.

[bartonc]

a better way to create a while loop (IMO) is using infinity loop.
eg

while 1:
    #statements...
    if some condition:
        break
    if another condition:
        break
 

this way, you can customize your loop according to different conditions, whereas in your example, you can only exit while loop on x>len(rate).
<snip>

I also like the infinite loop implementation and use enumerate() often. That said: Lest our readers get the wrong impression:

while x < len(rate):
    #statements...
    if some condition:
        break
    if another condition:
        break
 

is also valid.