python - 比较相邻值、删除相似对并比较新列表

Question

a = [1N, 1S, 1S, 2E, 2W, 1N, 2W] 假设我有一个这样的 list 。有没有一种方法可以进行以下比较。

Pseudo code: Iterate over list [1N, 1S, 1S, 2E, 2W, 1N, 2W], 1==1, delete those values. Iterate over
new list [1S, 2E, 2W, 1N, 2W], 1!=2, move on, 2==2 delete those values. Iterate
over new list [1S, 1N, 2W], 1==1, delete those values. Answer = 2W

到目前为止我所拥有的。

def dirReduc(arr):
    templist = []
    for i in range(1, len(arr)):
        a = arr[i - 1]
        b = arr[i]
        if a == b:
            templist = (arr[b:])
    (templist)
a = [1, 1, 1, 2, 2, 1, 2]
print(dirReduc(a)

测试用例产生正确的值，但我需要运行循环直到我只得到两个。这就是我被困的地方

Answer 1

如果你能理解问题，那么你只需要一段时间就可以根据需要进行迭代。

a = [1, 1, 1, 2, 2, 1, 2]
finished = False
while not finished:    # Iterate until finished = True
    finished = True    # That only happens when no repeated elements are found
    for i in range(len(a)-1):
        if a[i] == a[i+1]:
            a.pop(i)   # When removing the element i from a,
            a.pop(i)   # now the i + 1 is in the place of i
            print(a)
            finished = False
            break

它将产生:

[1, 2, 2, 1, 2]
[1, 1, 2]
[2]