On 2014-02-21 09:29, Alister wrote: > > >>> seriesxlist1 = ((0.0,), (0.01,), (0.02,)) > > >>> x2 = [x*x for (x,) in seriesxlist1] > > > > I tend to omit those parentheses and use just the comma: > > > > >>> x2 = [x*x for x, in seriesxlist1] > > I had not though of using unpacking in this way & would have written > > x2= [x[0]**2 for x in serisexlist1] > > I am not sure which is easier to read in this instance (single > element tupple) but unpacking would definitely be the way to go if > the tupple had multiple values.
With the single-value tuple, I tend to find the parens make it more readable, so I'd go with [x*x for (x,) in lst] whereas if they were multi-value tuples, I tend to omit the parens: [x*y for x,y in lst] though, tangentially, Python throws a SyntaxError if you try and pass a generator to a function without extra outer parens because it makes parsing them ambiguous otherwise: >>> x = sum(a+b for a, b in lst, 10) File "<stdin>", line 1 SyntaxError: Generator expression must be parenthesized if not sole argument >>> x = sum((a+b) for a,b in lst), 10) [no error] -tkc -- https://mail.python.org/mailman/listinfo/python-list
