给定输入:theList = [<userID>,<number_of_views>]
theList = [
[[3, 5], [1, 1], [2, 3]],
[[1, 2], [3, 5], [3, 0], [2, 3], [4, 2]],
[[1, 2], [3, 5], [3, 0], [2, 3], [4, 2]],
[[1, 2], [1, 1], [4, 2]]
]
expected output = [
[[3, 5], [2, 3], [1, 1]],
[[3, 5], [2, 3], [1, 2], [4, 2]],
[[3, 5], [2, 3], [1, 2], [4, 2]],
[[1, 3], [4, 2]]
]
for sublist in theList:
e.x -->
theList[3] = [[1,2], [1,1], [4,2]]
在这种情况下如何合并具有相同 userIDs = 1 的项目,并将所有对应的 View 与此 (userID=1) (2+1) = 3 个 View 相加到一个新列表中 --> [1,3]
expected theList[3] = [[1,3], [4,2]].
我如何为所有 theList 执行此过程?
非常感谢您花时间回答这个问题!
最佳答案
这是一种使用 collections.defaultdict
的方法。
例如:
from collections import defaultdict
theList = [
[[3, 5], [1, 1], [2, 3]],
[[1, 2], [3, 5], [3, 0], [2, 3], [4, 2]],
[[1, 2], [3, 5], [3, 0], [2, 3], [4, 2]],
[[1, 2], [1, 1], [4, 2]]
]
result = []
for i in theList:
r = defaultdict(int)
for j, k in i:
r[j] += k
result.append(list(r.items()))
print(result)
输出:
[[(3, 5), (1, 1), (2, 3)],
[(1, 2), (3, 5), (2, 3), (4, 2)],
[(1, 2), (3, 5), (2, 3), (4, 2)],
[(1, 3), (4, 2)]]
关于python-3.x - 匹配条件时合并多个相同长度的列表,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/57622583/