On Monday, December 8, 2014 3:52:53 AM UTC+5:30, Terry Reedy wrote: > On 12/7/2014 10:28 AM, Ivan Evstegneev wrote: > > Hi Shiyao, > > > > Now I see, that it was kind of dumb question... > > > >>>>> x = ([1, 2], [3, 4], [5, 6]) > >>>>> L = [] > >>>> [L.extend(i) for i in x] > > [None, None, None] > > Using a list comprehension for the expression side-effect, when you do > not actually want the list produced by the comprehension, is considered > bad style by many. There is nothing wrong with explicit loops.
Yes loops are ok If you want a solution along the lines you (OP) are seeking here is one: >>> from operator import add >>> reduce(add, [[1,2],[3,4]], []) [1, 2, 3, 4] >>> Notes 1. Terry's suggestion to use (the obvious) loop should be heeded 2. Which will also be more efficient 3. The reason I mention the reduce is that its a part of FP lore: Every map (and therefore comprehension) can be put into the form of a reduce. But not the contrary. -- https://mail.python.org/mailman/listinfo/python-list
