I agree with Jonathan, (find) and (exclude) are the best.
Filter is like "let me this in the result" (just the opposite sense),
and remove is like "real remove this from my database"
So... '*Find*' this in my rows, BUT also *Exclude *this from my results!
Alex F
El 28/10/2009 18:23, Jonathan Lundell escribió:
> On Oct 28, 2009, at 9:58 AM, mdipierro wrote:
>
>
>> On a third thougth. Mr Freeze original names are better (find and
>> filter it is).
>>
> Your use of 'filter' (or my confusion about it) for both cases
> illustrates its ambiguity. How about 'find' and 'exclude'?
>
>
>> I added slices too. Here is an example:
>>
>>
>> b=DAL('sqlite://storage')
>> db.define_table('a',Field('b'))
>> db.a.insert(b='aaa')
>> db.a.insert(b='aab')
>> db.a.insert(b='abb')
>> db.a.insert(b='bbb')
>>
>> ### return rows that match condition
>> rows=db(db.a.id>0).select().find(lambda row: row.b>0)
>>
>> #### sort rows
>> rows0 = rows.sort(lambda row: row.b.upper()):
>>
>> rows1=db(db.a.id>0).select()
>> ### move matching rows from rows1 to rows2
>> rows2=rows1.filter(lambda row: row.b>'b')
>>
>> ### get a slice of the rows
>> rows3=rows[1:3]
>>
>> They can be mixed and matched
>>
>> rows=(rows1|rows2|rows3).find(..)[:].filter(..).sort(..)
>>
>> Now one implement at DAL level most functions missing on GAE like OR,
>> LIKE, BELONGS.
>>
>> Massimo
>>
>> On Oct 28, 11:17 am, mdipierro<[email protected]> wrote:
>>
>>> Ok, I am going with filter (same as your find) and extract (same as
>>> your filter with some changes to make it faster and issue that caused
>>> it to skip some rows). In trunk now.
>>>
>>> Massimo
>>>
>>> On Oct 28, 10:51 am, "mr.freeze"<[email protected]> wrote:
>>>
>>>
>>>> Now I'm confused :) What if you just changed the 'where' to 'find'
>>>> and kept both. Filter should reduce the actual set, returning the
>>>> removed rows. Find should just return the matched rows.
>>>>
>>>
>>>> On Oct 28, 10:15 am, mdipierro<[email protected]> wrote:
>>>>
>>>
>>>>> OK I just put the where function in trunk but renamed it filter
>>>>> (sorry
>>>>> for the confusion).
>>>>>
>>>
>>>>> On Oct 28, 10:11 am, Joe Barnhart<[email protected]> wrote:
>>>>>
>>>
>>>>>> I know, that's what I'm saying.... the word "where" suggests it
>>>>>> is an SQL
>>>>>> verb but it has nothing to do with SQL. I was just thinking it
>>>>>> might be
>>>>>> confusing to new users of w2p.
>>>>>>
>>>
>>>>>> On Wed, Oct 28, 2009 at 6:32 AM, mr.freeze
>>>>>> <[email protected]> wrote:
>>>>>>
>>>
>>>>>>> No, anything post 'select' is done after the db call, including
>>>>>>> first
>>>>>>> () and last().
>>>>>>>
>>>
>>>>>>> On Oct 28, 2:51 am, Joe Barnhart<[email protected]> wrote:
>>>>>>>
>>>>>>>> I love the functionality, but doesn't calling the function
>>>>>>>> "where"
>>>>>>>> conjure up the SQL WHERE clause? I might think it was doing
>>>>>>>> something
>>>>>>>> with SELECT...WHERE in the underlying DB.
>>>>>>>>
>>>
>>>>>>>> -- Joe B.
>>>>>>>>
>>>
>>>>>>>> On Oct 27, 10:11 pm, "mr.freeze"<[email protected]> wrote:
>>>>>>>>
>>>
>>>>>>>>> Works! Would you be interested in these for sql.py Rows class?:
>>>>>>>>>
>>>
>>>>>>>>> def where(self,f):
>>>>>>>>> if not self.response:
>>>>>>>>> return None
>>>>>>>>> rows = []
>>>>>>>>> for i in range(0,len(self)):
>>>>>>>>> row = self[i]
>>>>>>>>> if f(row): rows.append(self.response[i])
>>>>>>>>> return Rows(self._db,rows,*self.colnames)
>>>>>>>>>
>>>
>>>>>>>>> def filter(self,f):
>>>>>>>>> if not self.response:
>>>>>>>>> return None
>>>>>>>>> rows = self.response
>>>>>>>>> removed = []
>>>>>>>>> for i in range(0,len(self)):
>>>>>>>>> row = self[i]
>>>>>>>>> if f(row):
>>>>>>>>> removed.append(rows[i])
>>>>>>>>> rows.remove(rows[i])
>>>>>>>>> return Rows(self._db,removed,*self.colnames)
>>>>>>>>>
>>>
>>>>>>>>> Example:
>>>>>>>>> db.define_table('things',Field('category'))
>>>>>>>>> rows = db(db.things.id>0).select()
>>>>>>>>> tests = rows.where(lamdba row: row.category=="test") #
>>>>>>>>> returns matches
>>>>>>>>> rows.filter(lamdba row: row.category=="test")# removes and
>>>>>>>>> returns
>>>>>>>>> removed
>>>>>>>>>
>>>
>>>>>>>>> On Oct 27, 10:49 pm, mdipierro<[email protected]> wrote:
>>>>>>>>>
>>>
>>>>>>>>>> Thanks. Just fixed in trunk!
>>>>>>>>>>
>>>
>>>>>>>>>> On Oct 27, 10:35 pm, "mr.freeze"<[email protected]> wrote:
>>>>>>>>>>
>>>
>>>>>>>>>>> I get a syntax error when using this. I believe line 2926 of
>>>>>>>>>>> Rows.__getitem__ needs to be changed from:
>>>>>>>>>>>
>>>
>>>>>>>>>>> if i>= len(self.response) or i< 0:
>>>>>>>>>>>
>>>
>>>>>>>>>>> ...to...
>>>>>>>>>>>
>>>
>>>>>>>>>>> if i>= len(self.response):
>>>>>>>>>>>
>>>
>>>>>>>>>>> since Rows.last() returns self[-1]
>>>>>>>>>>>
>>>
>>>
>>>
>
>
> >
>
>
--
Alejandro Fanjul Fdez.
[email protected]
www.mhproject.org
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