Question

我试图在每个循环中迭代一个arraylist保存连续值的最高/最低差异。

e1=([ 0 , 0,  0,  0, 15, 28, 28, 28, 27, 27, 35, 44, 43, 43, 42, 39])
Hodiffmax = 0
Hodiffmin = 0
for k in e1:
  diff1= e1[k+1] - e1[k]
  if diff1 > Hodiffmax:
      Hodiffmax=diff1
  if diff1 < Hodiffmin:
      Hodiffmin=diff1

问题是我得到一个＆＃34;索引超出范围＆＃34;错误。如何用[k + 1]迭代一个arraylist？我现在尝试了很多东西，但我没有变得更聪明。我感谢任何帮助！

编辑（既不起作用）：

for k in e1:
    for w in k:
      diff1= e1[w+1] - e1[w]
      if diff1 > Hodiffmax:
          Hodiffmax=diff1
      if diff1 < Hodiffmin:
          Hodiffmin=diff1

错误：对于w中的k - TypeError：＆＃39; numpy.int32＆＃39;对象不可迭代

Answer 1

使用[y - x for x, y in zip(e1, e1[1:])]，您可以获得连续的差异，而无需担心索引：

>>> e1 = [ 0 , 0,  0,  0, 15, 28, 28, 28, 27, 27, 35, 44, 43, 43, 42, 39]
>>> l = [y - x  for x, y in zip(e1, e1[1:])]
>>> Hodiffmax, Hodiffmin = max(l), min(l)
>>> Hodiffmax, Hodiffmin
15, -3

Answer 2

使用grouper recipe：

def grouper(iterable, n, fillvalue=None):
    "Collect data into fixed-length chunks or blocks"
    # grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx
    args = [iter(iterable)] * n
    return izip_longest(fillvalue=fillvalue, *args)

from itertools import izip_longest # required by grouper
i = [0, 0, 0, 0, 15, 28, 28, 28, 27, 27, 35, 44, 43, 43, 42, 39]
lowest = None
highest = None
for z,q in grouper(i, 2):
    v = z-q
    if v < lowest:
        lowest = v
    if v > highest:
        highest = v
print(lowest)
print(highest)

Answer 3

这里的问题是你正在迭代列表的元素。通过做

对于e1中的k：

NoMethodError: undefined method `css_value' for #<Capybara::Poltergeist::Node tag="div">将获取k上元素的值。 e1等等。你想要的是迭代列表的范围。

k=0, k=0, k=0, k=0, k=15, k=28

for k in range(len(e1)):将获取k上的索引值。 e1等等。我想你正在寻找这样的东西：

k=0, k=1, k=2, k=3, k=4, k=5

通过arraylist迭代计算python中连续值的差异

3 个答案: