En Fri, 18 Apr 2008 15:10:09 -0300, <[EMAIL PROTECTED]> escribió: > lessons = self.lesson_data["lessons"] > if lesson_type: > lessons = [x for x in lessons if x["type"] == lesson_type] > > Changes: > - generator expression instead of filter
The above is not a generator expression, it's a list comprehension. They look similar. This is a list comprehension: py> a = [x for x in range(10) if x % 2 == 0] py> a [0, 2, 4, 6, 8] Note that it uses [] and returns a list. This is a generator expression: py> g = (x for x in range(10) if x % 2 == 0) py> g <generator object at 0x00A3D580> py> g.next() 0 py> g.next() 2 py> for item in g: ... print item ... 4 6 8 Note that it uses () and returns a generator object. The generator is a block of code that runs lazily, only when the next item is requested. A list is limited by the available memory, a generator may yield infinite items. > Cheers again. This is very valuable for me. I am a true believer > that if one takes care in the smallest of methods then the larger code- > base will be all the better. Sure. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
