Comments on: A Simple Django Truncate Filter

By: Paul

Paul — Thu, 25 Feb 2010 17:56:48 +0000

the indentation was lost in the paste. here it is:

http://gist.github.com/314819

By: Paul

Paul — Thu, 25 Feb 2010 17:53:53 +0000

Thanks that’s useful but I found two bugs with this:
- it throws an error if there’s no space in the string before max_length
- the get the character right after truncation, you should use value[max_length], not value[max_length + 1] which also solves the issue chris reported.
Heres the fixed version:

from django import template
register = template.Library()

@register.filter(“truncate_chars”)
def truncate_chars(value, max_length):
if len(value) <= max_length:
return value

truncd_val = value[:max_length]
if value[max_length] != ” “:
rightmost_space = truncd_val.rfind(” “)
if rightmost_space != -1:
truncd_val = truncd_val[:rightmost_space]

return truncd_val + “…”

By: Neum

Neum — Tue, 09 Feb 2010 21:08:21 +0000

Excellent! That was exactly what I was looking for. I agree, this should be in Django proper. Until then, you saved me 10 min. Thanks!

By: Chris Robinson

Chris Robinson — Wed, 07 Oct 2009 00:53:13 +0000

Worked beautifully thanks! No idea why truncating by characters isn’t part of the default set of django filters

By: Daniel Karlsson

Daniel Karlsson — Tue, 19 May 2009 20:25:04 +0000

my django expert informed me that strings are lists and therefore we can use {{ some_list|slice:”:20″ }} or more specific {{ some_string | slice:”:20″}}

By: Graham King

Graham King — Fri, 01 May 2009 22:36:46 +0000

Exactly what I needed. Thank you.

By: Chris

Chris — Mon, 02 Feb 2009 22:25:01 +0000

Minor error at a boundary condition. You can fix it by changing line 8 to:

if not len(value) == max_length+1 and value[max_length+1] != ” “:

By: SmileyChris

SmileyChris — Sun, 10 Aug 2008 23:40:06 +0000

So kinda like http://code.djangoproject.com/ticket/5025 ?

Interesting idea about cutting it back to the last word, but if you’re that worried about truncating characters, I’d suggest it just inserts the ellipsis after truncating to length-3.