On Thursday, September 16, 2010 08:18:20 am Jacek Kałucki wrote: > Użytkownik John Fabiani napisał: > > First I did not know you could pass 'param' to gather data. So my > > understanding of the use of scan maybe completely wrong. Is that param > > used by the function/method to place data into? > > > > I thought the second parameter of the scan method was to determine the > > direction of the scan (forward vs reverse). And I have only used the > > scan method as simple way to reiterate over the bizojb records. With > > that in mind what would the return value represent? That I completed > > the scan. But I don't always completely scan all records. > > > > So I guess I could use some enlightment on this subject. > > This method has the following declaration: > def scan(self, func, *args, **kwargs) > > It means, that you can pass to 'func' any parameter except named > parameter 'reverse'. > Of course, scan() can be used to execute some operations on rows - I > think it was primary Ed's goal. > But why don't use it for something more practical, like calculations or > testing for some conditions? > It would be a pity to waste its potential. > So, we are at the beginning, how to retrieve result? Ah! Now I see what you are after. But first let me say you made me think outside my comfort zone - and thanks for that.
I'm old school. If I need a subset of my data I turn to SQL almost immediately. Years ago when Dabo added the ability to execute sql statements against datasets was a very good day for me. But there are times that SQL will not meet the requirements. To be honest I haven't run across very many times where SQL was not enough to get my data into the shape I wanted. So when I can't use SQL I have used the basic methods of filter and scan to get that done. I have also used deep.copy() and then executed multi- SQL statement against the copied data. Johnf _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/dabo-dev Searchable Archives: http://leafe.com/archives/search/dabo-dev This message: http://leafe.com/archives/byMID/[email protected]
