OK, good point. In that case, I'll just send a patch for .find and .sort so they return the original self.records items so .render will work properly.
Anthony On Wednesday, January 8, 2014 11:47:24 AM UTC-5, Massimo Di Pierro wrote: > > The problem is speed. I believe the getitem should be as fast as possible. > This was changed before so that the trasformation of the rows occurred only > once and not every time a row column is accessed. > > On Jan 8, 2014, at 8:41 AM, Anthony wrote: > > Let's discuss on the developers > list<https://groups.google.com/forum/?fromgroups=#!topic/web2py-developers/k2D6MVfBEYo> > . > > On Tuesday, January 7, 2014 9:52:16 PM UTC-5, Joe Barnhart wrote: >> >> Maybe the best answer is to change Row so that it always holds the full >> set of keys (table:field) and change the __getitem__ method to look up the >> key recursively if only one part is provided. Here is a sample method >> which implements this strategy of testing keys for dicts within dicts. Our >> case is a little simpler since we never "recurse" more than one level deep. >> >> def _finditem(obj, key): >> if key in obj: return obj[key] >> for k, v in obj.items(): >> if isinstance(v,dict): >> item = _finditem(v, key) >> if item is not None: >> return item >> >> >> This has the advantage of working with existing code and preserving as >> much information as possible in the Row object. I have a feeling this >> could make the internals of web2py a good deal more consistent. Less >> testing for special cases is always good! >> >> -- Joe B. >> >> On Tuesday, January 7, 2014 3:48:39 PM UTC-8, Anthony wrote: >>> >>> Note, same problem with .sort (it modifies the Row objects in >>> self.records), so we should probably fix that as well (will be a bit more >>> complicated). >>> >>> Anthony >>> >>> On Tuesday, January 7, 2014 11:03:56 AM UTC-5, Anthony wrote: >>>> >>>> The Rows.find() method does the following: >>>> >>>> for row in self: >>>> if f(row): >>>> if a<=k: records.append(row) >>>> k += 1 >>>> if k==b: break >>>> >>>> In a Rows object, there is self.records, which is a list of Row >>>> objects. Each Row object has at least one top-level key with the table >>>> name, and the record is stored in the value associated with that key: >>>> >>>> <Row {'person': {'first_name': 'Bob', 'last_name': 'Smith'}}> >>>> >>>> When .find() is called on a Rows object with compact=True, the __iter__ >>>> method (called by the "for row in self" loop) returns a transformed >>>> version >>>> of each Row object, removing the top-level table key: >>>> >>>> <Row {'first_name': 'Bob', 'last_name': 'Smith'}> >>>> >>>> I believe this is an unnecessary transformation, and it is what is >>>> subsequently causing the .render() method to fail (the .render() method >>>> expects the top-level table key to be there, whether or not compact=True). >>>> I propose the following change to .find(): >>>> >>>> for i, row in enumerate(self): >>>> if f(row): >>>> if a<=k: records.append(self.records[i]) >>>> k += 1 >>>> if k==b: break >>>> >>>> The above code appends self.records[i] instead of row, which preserves >>>> the original Row objects instead of including transformed objects. Anyone >>>> see any problems with that change? >>>> >>>> Also, is there any reason all of the Rows methods (i.e., find, exclude, >>>> __and__, __or__) should not be preserving the "compact" attribute of the >>>> original Rows object? Perhaps we should change them all to do so. (Note, >>>> this is a separate issue unrelated to the above problem with .find() and >>>> .render().) >>>> >>>> Anthony >>>> >>>> On Tuesday, January 7, 2014 10:47:28 AM UTC-5, Anthony wrote: >>>>> >>>>> .render() works fine on Rows objects with compact=True, and it also >>>>> works fine on the results of .sort(), .exclude(), &, and | operations. >>>>> The >>>>> only problem is with the results of .find() operations when the original >>>>> Rows object has compact=True. The problem is that the .find() method >>>>> modifies the Row objects in self.records when compact=True, which it >>>>> probably should not due. >>>>> >>>>> Aside from this issue, perhaps the various Rows methods should >>>>> preserve the "compact" attribute -- not sure why they don't. >>>>> >>>>> Forwarding to the developers list for discussion. >>>>> >>>>> Anthony >>>>> >>>>> On Tuesday, January 7, 2014 3:10:00 AM UTC-5, Joe Barnhart wrote: >>>>>> >>>>>> I've been experimenting with the render method of the Rows class, and >>>>>> I am very impressed. But one drawback I found is that the Rows object >>>>>> must >>>>>> have its value set to "compact=False" to work properly with render(). >>>>>> It >>>>>> isn't a problem if the Rows object is used directly without any >>>>>> operators, >>>>>> but I discovered that many, if not most, Rows methods do not preserve >>>>>> the >>>>>> "compact" setting. >>>>>> >>>>>> For example. if you "sort" the Rows, it leaves compact=True. Ditto, >>>>>> if you use "extract" or "find" on the Rows object. The "&" and "|" >>>>>> operators also set the compact variable to "True". The upshot is that >>>>>> you >>>>>> can't use any of these operators on the Rows object and then use >>>>>> "render" >>>>>> on the resulting object. >>>>>> >>>>>> It is a simple change to add the preservation of the "compact" flag >>>>>> during any of these steps, but I'm unsure if this will break existing >>>>>> code. >>>>>> Other than coming up with a completely parallel set of methods, which >>>>>> leave compact set the way it came in, I can't think of another approach >>>>>> will be provably backwards-compatible. >>>>>> >>>>>> Here is an example: >>>>>> >>>>>> >>>>>> def __and__(self,other): >>>>>> if self.colnames!=other.colnames: >>>>>> raise Exception('Cannot & incompatible Rows objects') >>>>>> records = self.records+other.records >>>>>> return Rows(self.db,records,self.colnames) >>>>>> >>>>>> >>>>>> Becomes: >>>>>> >>>>>> >>>>>> def __and__(self,other): >>>>>> if self.colnames!=other.colnames: >>>>>> raise Exception('Cannot & incompatible Rows objects') >>>>>> records = self.records+other.records >>>>>> return Rows(self.db,records,self.colnames,compact=(self.compact >>>>>> or other.compact)) >>>>>> >>>>>> >>>>>> In the case above, the flag compact will be set True if either of the >>>>>> participating Rows object is also "compact". My logic is, if you've >>>>>> lost >>>>>> the "table" values on either Rows object, you may as well lose them on >>>>>> the >>>>>> combined set. >>>>>> >>>>>> What do you think? >>>>>> >>>>>> -- Joe B. >>>>>> >>>>>> >>>>>> > -- > -- mail from:GoogleGroups "web2py-developers" mailing list > make speech: web2py-d...@googlegroups.com <javascript:> > unsubscribe: web2py-develop...@googlegroups.com <javascript:> > details : http://groups.google.com/group/web2py-developers > the project: http://code.google.com/p/web2py/ > official : http://www.web2py.com/ > --- > You received this message because you are subscribed to the Google Groups > "web2py-developers" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to web2py-develop...@googlegroups.com <javascript:>. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. 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