[Zope] Checking sequence-index using dtml-if

[Curtis Maloney]

On Wednesday 21 February 2001 14:02, Jeff Hotz wrote:
> Thanks.
>
> Could you please help me understand the syntax of the statement you
> suggested?
>
> Specifically, this portion      ZSQLMethod()[:3]
>
> Additionally, with this method, is there a way to process all records
> starting with a certain number until eof()?
>

OK.  Starting with the line:

<dtml-in expr="an_sql_method()[:3]">

(this is exactly the same as <dtml-in "an_sql_method()[:3]">  but is more 
clear to the human that it's an expression.)

The dtml-in portion, as you know, means "iterate over the elements in this 
list".

expr=""  means 'evaluate this string as Python'

an_sql_method()  is fairly obvious... and since it returns a List, you can 
'slice' the list, using [:3], which means "the first 3 elements".

If you wanted to start with the fourth, and continue on, you would use:

an_sql_method()[4:]

Note, this is not the same as:

an_sql_method()[4]

which would return ONLY the fourth element.  This is standard Python syntax, 
which is fairly clearly documented in the Python language documentation.

> Thanks again for your help.
>


Have a better one,
	Curtis Maloney.