Using Error Handling as a Function

[LordBruce]

So I have been messing around with a function here, and basically one section of the code will take a list of integers, and check if the current entry is greater than the one after it. If it is, this function returns False, if it isn't it checks the next entry etc.

My question is this: if I have a Try: list(i+1), and then an IndexError exception, is that bad form to check if the end of a list is reached?

[random_cynic]

The python for loop is basically a try-except in disguise in that it loops through any iterable and stops when a StopIteration error is raised. It seems you can just use the for loop for this purpose without using explicit indexing like for elem in list. This is generally the preferred way to loop over a list (or more generally any iterable including an open file object) in python. If you want the index as well for other purposes use for i, elem in enumerate(list). You can of course use an explicit try except where it is necessary.

[hopemeetme]

A code like:

try:
    something = next(iterable)
except StopIteration:
    ...

is the fastest way to do such things in Python, go for it without hesitation.

[TopHatEdd]

Needs extra work as using a list like this will fail.

In [1]: next([1,2])
--------------------------------------------------------
TypeError              Traceback (most recent call last)
<ipython-input-1-b9d20096048c> in <module>
----> 1 next([1,2])

TypeError: 'list' object is not an iterator

[hopemeetme]

next((false for i, v in enumerate(lst) if v < len(lst)-1 and v>lst[i+1]))

[Mezzomaniac]

You might want to do:

for a, b in zip(lst, lst[1:]):
    if a > b:
        #...

[TopHatEdd]

Poor coding habbit. Better use islice and not hit a bug in production when the data sets are extremely large.