What does the at sign do?

[guruyaya]

I'm reading a lot of python code lately, django code to be exact, and
I keep bumping into expressions that look like this
@register.filter

I see nothing importing @register, so I assume it's not just a
function name. Yet I cannot figure where this @ sign came from.
I hope I'm not just forgetting something out of the very basics.

Thanks in advance
Yaya

 

[r]

Google "python decorators"

 

[Martin v. Löwis]

I'm reading a lot of python code lately, django code to be exact, and

I keep bumping into expressions that look like this
@register.filter

I see nothing importing @register, so I assume it's not just a
function name.

That can't be. register must be a bound name - not necessarily an
imported function; it could also be something being set through
assignment (register = Registry()).

Yet I cannot figure where this @ sign came from.

That's a function decorator; see PEP 318.

Regards,
Martin