3 ms·

> a.zip(b).map(func1).filter(func2).forall(func3) Lets make this a somewhat concrete example. --- heights = [1,2,3] widths = [4,5,6] # printing area greate

by bko 6y ago

> a.zip(b).map(func1).filter(func2).forall(func3) Lets make this a somewhat concrete example. --- heights = [1,2,3] widths = [4,5,6] # printing area greater than 10 # functional heights.zip(widths).map(to_area).filter(lambda area: area > 10).forall(lambda a: print("Area " + a) #Verbose way hw_zipped = zip(a,b) areas = hw_zipped.map(to_inches) big_areas = areas.filter(a: a > 10) for a in big_areas: print("Area " + a) --- Which do you prefer? I would argue the right level of abstraction is the functional way in this example, and its often the case in my experience, especially in python where you don't often use a namespace to store these intermediary variables and you have can't rely on typing

syrrim 6y ago
for x, y in zip(a,b): area = to_area(x, y) if area > 10: print(f"Area {area}") >in python where you don't often use a namespace to store these intermediary variables Hm? Most python code is within a function, in my experience.
- bko 6y ago
  You can abstract it out to a function but I think its overkill, even if you generalize to something like print_area_filter(heights, widths, value, cmp) or whatever If its not in a function, your example may (or may not depending on length if either a or b have a length of zero) create a floating variable called area out there.
claytonjy 6y ago
As another point of comparison, as of python 3.8 you can do this in one list comp without nesting or double-computing areas with the walrus: result = [area for x,y in zip(heights,widths) if (area := to_area(x,y)) > 10] I don't think that's very easy to read; I'd opt for two list comps like areas = [to_area(x,y) for x,y in zip(heights,widths)] result = [area for area in areas if area > 10] But I agree with OP that map+filter is easier to read.
- bko 6y ago
  I agree. My main problem is I don't want intermediary variables floating around. Especially something like "areas". If python localized variables to a blocked namespace, I wouldn't mind In scala: --- val widths = Seq(1,2,3) val heights = Seq(4,5,6) widths.zip(heights).foreach { case (w, h) => { val area = w * h if (area > 10) { println(s"Area: ${area}") } }} println(area) // error: not found: value area
- joshuamorton 6y ago
  You can do this without the walrus in a one liner as well, I believe: [area for area in (to_area(x, y) for x, y in zip(h, w)) if area > 10] or generally, you can take a multiline statement like the one you have and replace named value with its expression. Add some indentation and it's not too bad: [area for area in (to_area(x, y) for x, y in zip(h, w)) if area > 10]

by bko 6y ago

syrrim 6y ago

for x, y in zip(a,b): area = to_area(x, y) if area > 10: print(f"Area {area}") >in python where you don't often use a namespace to store these intermediary variables Hm? Most python code is within a function, in my experience.

bko 6y ago
You can abstract it out to a function but I think its overkill, even if you generalize to something like print_area_filter(heights, widths, value, cmp) or whatever If its not in a function, your example may (or may not depending on length if either a or b have a length of zero) create a floating variable called area out there.

claytonjy 6y ago

As another point of comparison, as of python 3.8 you can do this in one list comp without nesting or double-computing areas with the walrus: result = [area for x,y in zip(heights,widths) if (area := to_area(x,y)) > 10] I don't think that's very easy to read; I'd opt for two list comps like areas = [to_area(x,y) for x,y in zip(heights,widths)] result = [area for area in areas if area > 10] But I agree with OP that map+filter is easier to read.

bko 6y ago
I agree. My main problem is I don't want intermediary variables floating around. Especially something like "areas". If python localized variables to a blocked namespace, I wouldn't mind In scala: --- val widths = Seq(1,2,3) val heights = Seq(4,5,6) widths.zip(heights).foreach { case (w, h) => { val area = w * h if (area > 10) { println(s"Area: ${area}") } }} println(area) // error: not found: value area
joshuamorton 6y ago
You can do this without the walrus in a one liner as well, I believe: [area for area in (to_area(x, y) for x, y in zip(h, w)) if area > 10] or generally, you can take a multiline statement like the one you have and replace named value with its expression. Add some indentation and it's not too bad: [area for area in (to_area(x, y) for x, y in zip(h, w)) if area > 10]