假设我有以下排序列表:
a = ['8EF5CD1B', 'B1392DB3', '59770CD6', 'BD23F32A', '4EFA3222']
b = ['8EF5CD1B', '96276D30', 'B1392DB3', '59770CD6', '4EFA3222']
c = ['96276D30', 'B1392DB3', 'BD23F32A', '59770CD6']
我希望它们通过填充较低优先级列表中的空白来合并排序。
>>> from itertools import permutations
>>> LISTS = (a, b, c)
>>> for (first, second) in permutations(LISTS, 2):
... print((LISTS.index(first), LISTS.index(second)), magic(first, second))
...
(0, 1) ['8EF5CD1B', '96276D30', 'B1392DB3', '59770CD6', 'BD23F32A', '4EFA3222']
(0, 2) ['8EF5CD1B', '96276D30', 'B1392DB3', '59770CD6', 'BD23F32A', '4EFA3222']
(1, 0) ['8EF5CD1B', '96276D30', 'B1392DB3', '59770CD6', 'BD23F32A', '4EFA3222']
(1, 2) ['8EF5CD1B', '96276D30', 'B1392DB3', 'BD23F32A', '59770CD6', '4EFA3222']
(2, 0) ['96276D30', '8EF5CD1B', 'B1392DB3', 'BD23F32A', '59770CD6', '4EFA3222']
(2, 1) ['8EF5CD1B', '96276D30', 'B1392DB3', 'BD23F32A', '59770CD6', '4EFA3222']
>>>magic(*LISTS)
['8EF5CD1B', '96276D30', 'B1392DB3', '59770CD6', 'BD23F32A', '4EFA3222']
正如您在获得第二名中所看到的那样(0,1)
,96276D30
因为列表中存在一个空白b
。在订单冲突的情况下,优先级转到第一个参数。魔术函数应该使用两个以上的参数,就像上面的例子一样。我编写了一个有效的代码,但对于像这样看似简单的任务来说,它太丑了(而且可能太慢了)。
MAX_ITERATIONS = 1000
class UnjoinableListsError(Exception): pass
def magic(*lists, iterations=MAX_ITERATIONS):
"""
Returns a joint sorted list of presorted lists (or tuples).
First it checks for common items, then it defines a gap list to put
non-commons in. Finally it mixes them all. If items of more presorted
list (or tuple) competes for a gap place, they will sorted in order
of their parents were in arguments.
"""
def sort_two(first, second):
commons = [item for item in first if item in second]
gap_list = [[] for i in range(len(commons)+1)]
for l in (first, second):
gap_item = []
sliced = []
for common_item in commons:
common_i = l.index(common_item)
sliced.append((list(l[:common_i]), list(l[common_i+1:])))
gap_item.append(sliced[0][0])
for j in range(len(sliced) - 1):
gap_item.append([item for item in sliced[j][1]
if item in sliced[j+1][0]])
gap_item.append(sliced[-1][1])
for j, item in enumerate(gap_item):
gap_list[j].extend([i for i in item if i not in commons])
result = []
result.extend(gap_list[0])
for i in range(len(commons)):
result.append(commons[i])
result.extend(gap_list[i+1])
return result
result = lists[0]
index_set = {i for i in range(1, len(lists))}
it = iterations
while index_set and it > 0:
it -= 1
if it == 0:
raise UnjoinableListsError('The lists at argument index {}'+
'are unjoinable.'.format(str(index_set)))
i = index_set.pop()
try:
result = sort_two(result, lists[i])
except:
index_set.add(i)
return result
我错过了一些清晰而简单的解决方案吗?感谢您的回答。