On 02/10/2015 08:53 AM, Ian Kelly wrote: > On Tue, Feb 10, 2015 at 9:44 AM, Ethan Furman <et...@stoneleaf.us> wrote: >> On 02/09/2015 08:46 PM, Chris Angelico wrote: >>> >>> class Grid: >>> blah blah >>> >>> def __iter__(self): >>> for row in range(self._rows): >>> for col in range(self._cols): >>> if self._grid[row][col]: >>> yield self._grid[row][col] >> >> I strongly suggest you remove the >> >> if self._grid[row][col]: >> >> line. >> >> Best case scenario: the entire grid is blank, and iterating through it does >> nothing. >> >> Worst case scenario: only some elements evaluate as False, so your loop >> doesn't execute the full number of times; i.e. >> with a grid of 4x5 with 7 blank cells you get 13 iterations -- probably not >> what was expected. > > Depends on what the expected behavior is -- is every grid position > something that should be included in the iteration, or are we looking > at elements of a container where some possible locations may be empty? > You don't expect a dict iteration to yield empty buckets, for example. > > I have some code that looks similar to this, which is an iterator for > a chess board that yields the contained pieces. It doesn't really make > sense in that case to yield empty squares.
Cool, thanks for the correction. -- ~Ethan~
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