5 ms·

What is the problem with that? Number + Number = number list + list = list str + str = str

by progrn 11y ago

vessenes 11y ago
It's a bit of cognitive load. It's not clear whether or not [1,2] + [3,4] should equal [1,2,3,4] or [4,6]. Keeping track of that, (oh wait, this is a numpy array, not a python list...) and things like that expand the amount of the language that a programmer must keep in her head at any one time, and are the definition of complexity. There's no known silver bullet for the complexity / power tradeoff, which is why we get so many cool languages!
- wpietri 11y ago
  Is there some language where [4,6] is the output? That strikes me as serving some use case that I've never come across. Whereas having two lists and wanting to end up with one list with all the elements is a very common need.
  - gknoy 11y ago
    I believe it would be in Matlab, as [1, 2] + [3, 4] would be considered matrix addition, in which one adds elements in corresponding places. Numpy (as mentioned in the GP) probably does similar.
    - wpietri 11y ago
      Ah, ok, thanks. Right, matrix math is is the use case I was looking for.
  - topogios 11y ago
    In R: > a <- array(c(1,2)) > b <- array(c(3,4)) > a + b [1] 4 6 > class(a + b) [1] "array"
  - vessenes 11y ago
    Yes, python. In [1]: import numpy as np In [2]: a = np.array([1,2]) In [3]: b = np.array([3,4]) In [4]: a+b Out[4]: array([4, 6])
    - bwohlergo 11y ago
      we are talking about Lists, not arrays from an unrelated library which has to be installed first. what you've done there is simply dishonest In [1]: a = [1,2] In [2]: b = [4,5] In [3]: print(a+b) Out [1, 2, 4, 5]
  - Animats 11y ago
    Is there some language where [4,6] is the output? Yes. Python: >>> x = numpy.array([1,2]) >>> y = numpy.array([3,4]) >>> x + y array([4, 6]) For extra fun: >>> x + [3,4] array([4, 6]) >>> [1,2] + y array([4, 6]) but, of course: >>> [1,2] + [3,4] [1, 2, 3, 4]
  - deleted 11y ago
    [deleted]

What is the problem with that? Number + Number = number list + list = list str + str = str

by progrn 11y ago

What is the problem with that? Number + Number = number list + list = list str + str = str

It's a bit of cognitive load. It's not clear whether or not [1,2] + [3,4] should equal [1,2,3,4] or [4,6]. Keeping track of that, (oh wait, this is a numpy array, not a python list...) and things like that expand the amount of the language that a programmer must keep in her head at any one time, and are the definition of complexity. There's no known silver bullet for the complexity / power tradeoff, which is why we get so many cool languages!

wpietri 11y ago
Is there some language where [4,6] is the output? That strikes me as serving some use case that I've never come across. Whereas having two lists and wanting to end up with one list with all the elements is a very common need.
- gknoy 11y ago
  I believe it would be in Matlab, as [1, 2] + [3, 4] would be considered matrix addition, in which one adds elements in corresponding places. Numpy (as mentioned in the GP) probably does similar.
  - wpietri 11y ago
    Ah, ok, thanks. Right, matrix math is is the use case I was looking for.
- topogios 11y ago
  In R: > a <- array(c(1,2)) > b <- array(c(3,4)) > a + b [1] 4 6 > class(a + b) [1] "array"
- vessenes 11y ago
  Yes, python. In [1]: import numpy as np In [2]: a = np.array([1,2]) In [3]: b = np.array([3,4]) In [4]: a+b Out[4]: array([4, 6])
  - bwohlergo 11y ago
    we are talking about Lists, not arrays from an unrelated library which has to be installed first. what you've done there is simply dishonest In [1]: a = [1,2] In [2]: b = [4,5] In [3]: print(a+b) Out [1, 2, 4, 5]
- Animats 11y ago
  Is there some language where [4,6] is the output? Yes. Python: >>> x = numpy.array([1,2]) >>> y = numpy.array([3,4]) >>> x + y array([4, 6]) For extra fun: >>> x + [3,4] array([4, 6]) >>> [1,2] + y array([4, 6]) but, of course: >>> [1,2] + [3,4] [1, 2, 3, 4]
- deleted 11y ago
  [deleted]