Parse each line by character location

[Cameron Laird]

In article <mailman.3467.1225819771.3487.python-list at python.org>,
Tim Chase  <python.list at tim.thechases.com> wrote:
>> I hope this is the right place to ask, but I am trying to come up with
>> a way to parse each line of a file. Unfortunately, the file is neither
>> comma, nor tab, nor space delimited. Rather, the character locations
>> imply what field it is.
>> 
>> For example:
>> 
>> The first ten characters would be the record number, the next
>> character is the client type, the next ten characters are a volume,
>> and the next three are order type, and the last character would be an
>> optional type depending on the order type.
>
>Sounds like you could do something like
>
>   recno_idx = slice(0,10)
>   client_idx = slice(10, 11)
>   volume_idx = slice(11,11+10)
>   order_type_idx = slice(11+10, 11+10+3)
			.
			.
			.
!?  That seems to me confusingly far from a working solution,
at least in comparison to

    recno_idex = the_line[0:10]
    client_idx = the_line[10:11]
	...

What am I missing?