"not in" does the break, and since it's built-in, is faster than the
user loop. More important, it's more clear what's going on.
sets should be smaller and faster than dicts, and are definitely more
clear.
Yes, some things that have == tests can't be used as set members. The
code that sets self.choices can decide whether to use a set using
something like:
google/appengine/db/__init__.py line 333 with
try:
self.choices = set(value)
except:
self.choices = value
Note that both "not in" and the current loop work with both sets and
lists.
On Oct 14, 3:32 pm, djidjadji <[EMAIL PROTECTED]> wrote:
> Why not break when a match is found
> if self.choices:
> match = False
> for choice in self.choices:
> if choice == value:
> match = True
> break
> if not match:
> raise BadValueError('Property %s is %r; must be one of %r' %
> (self.name, value,self.choices))
>
> Maybe faster to make self.choices a dictionary.
> The keys are in a hash table and that is faster then linear searching
>
> self.choices = { choice1:True, choice2:True }
> ......
> if self.choices:
> if not self.choices.get(value):
> raise BadValueError('Property %s is %r; must be one of %r' %
> (self.name, value,self.choices))
>
> 2008/10/13 Andy Freeman <[EMAIL PROTECTED]>:
>
>
>
>
>
> > google/appengine/db/__init__.py starting at line 401 is:
> > if self.choices:
> > match = False
> > for choice in self.choices:
> > if choice == value:
> > match = True
> > if not match:
> > raise BadValueError('Property %s is %r; must be one of %r' %
> > (self.name, value,
> > self.choices))
>
> > It could be:
> > if value not in (self.choices or (value,)):
> > raise BadValueError('Property %s is %r; must be one of %r' %
> > (self.name, value,
> > self.choices))
>
> > "not in" will stop when it finds a match and may be faster for each
> > element checked.
>
> > Note that making self.choices a set would make the "not in" test O(1).-
> > Hide quoted text -
>
> - Show quoted text -
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