Re: [Zope] brain hurts regarding dynamic fcn args in Python
Jeff Sasmor writes:
Is there a (straightforward?) way to dynamically compose function
argument lists? For example, in C, you can write"
f(arg1, arg2, (conditional expression)?(val for TRUE state):(val for FALSE state)).
Others have pointed out, that you can use
"and" and "or" to emulate "? ... : ...".
Be careful, there are dangers, because the emulation is not faithful.
In my case here in Zope, sometimes I have to search a ZCatalog
prior to displaying the results in a dtml-in looping construct.
dtml-in
"Catalog.searchResults(meta_type='EventDoc',event_date=[first,last],event_date_usage='range:min:max',sort_on='event_date
')"
/dtml-in
Now if the 'moderated' property is active I want to add the keyword arg
reviewed='on'
to the arg list at the time that the searchResults method is invoked.
In some cases, you could use:
...(..., reviewed= moderated and 'on', ...)
This will define "reviewed". It will have a Python "false" value
if moderated is "false", otherwise the value 'on'.
If your function uses code like:
"if kw.has_key('reviewed') and kw['reviewed': ..."
this will work. If the second and term is missing, if won't.
I do not know, what code ZCatalog uses. Try it out or
look into the source.
Dieter
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RE: [Zope] brain hurts regarding dynamic fcn args in Python
Is there a (straightforward?) way to dynamically compose function
argument lists? For example, in C, you can write"
f(arg1, arg2, (conditional expression)?(val for TRUE
state):(val for FALSE state)).
This can be emulated in Python by the boolean logic:
( ({conditional expression}) and {TRUE val} ) or {FALSE val}
e.g.
a = ( ( (x 1) and "biggerthanone" ) or "smallerthanone" )
x = 0
a = ( (x 1) and "biggerthanone" ) or "smallerthanone"
a
'smallerthanone'
Or one can embed a fcn call within an argument list in order
to supply a
needed function parameter.
Hrm.. I *think* this will work as a function argment. Sure.. why not?
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RE: [Zope] brain hurts regarding dynamic fcn args in Python
Oops, I'm not quite right about this. This FAQ explains it better...
http://www.python.org/doc/FAQ.html#4.16
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Monday, June 19, 2000 4:51 PM
To: [EMAIL PROTECTED]
Subject: RE: [Zope] brain hurts regarding dynamic fcn args in Python
Is there a (straightforward?) way to dynamically compose function
argument lists? For example, in C, you can write"
f(arg1, arg2, (conditional expression)?(val for TRUE
state):(val for FALSE state)).
This can be emulated in Python by the boolean logic:
( ({conditional expression}) and {TRUE val} ) or {FALSE val}
e.g.
a = ( ( (x 1) and "biggerthanone" ) or "smallerthanone" )
x = 0
a = ( (x 1) and "biggerthanone" ) or "smallerthanone"
a
'smallerthanone'
Or one can embed a fcn call within an argument list in order
to supply a
needed function parameter.
Hrm.. I *think* this will work as a function argment. Sure.. why not?
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