按每个子列表中的某些值对子列表分组列表

Question

我有一个包含列表的字典。例如，

{1: [[sender11, receiver11, text11, address11]], 
2: [[sender21, receiver21, text21, address21], [sender22, receiver22, text22, address22]], 
3: [[sender31, receiver31, text31, address31], [sender32, receiver32, text32, address32], [sender33, receiver33, text33, address33]] 
4: [[sender41, receiver41, text41, address41], [sender42, receiver42, text42, address42], [sender43, receiver43, text43, address43], [sender44, receiver44, text44, address44]]} 

我想要做的是，对于那些包含有2个或多个元素（即dict[2]，在这个例子中dict[3]和dict[4]）的列表字典元素，我做的sender, receiver, text的每一个的比较列表值。对于每组列表值相同的sender, receiver, text，我会做一些事情。

因此，例如，在dict[3]，如果sender31, receiver31, text31如sender32, receiver32, text32和sender33, receiver33, text33相同的值，然后我会做所有的3个列表值的东西。

说，在dict[4]，如果sender41, receiver41, text41是相同的值sender42, receiver42, text42，而sender43, receiver43, text43来自sender41, receiver41, text41相同的值sender44, receiver44, text44，但不同的，然后我会在这2组独立工作。

我写了一个Python脚本，几乎蛮力比较的sender21, receiver21, text21和sender22, receiver22, text22的值，即

if sender21 == sender22 and receiver21 == receiver22 and text21 == text22: 
    # Do something 

这是不是有效，因为它仅适用于2个列表值，但我不知道我应该如何实现这使得它适用于任何号码表的值大于1

Answer 1

我觉得defaultdict是去这里明显的方式：

from collections import defaultdict 

def collate(seq): 
    groups = defaultdict(list) 
    for subseq in seq: 
     groups[tuple(subseq[:3])].append(subseq[3]) 
    return groups 

根据您的实际数据，您可能会用上述功能替换上述功能中的tuple(subseq[:3])。 (subseq[1], subseq[4], subseq[5])，或附加subseq[3]与subseq本身......这将取决于你在做什么与数据。

但是，键必须是元组而不是列表，因为键必须是不可变的。

例子：

>>> data = [ 
...  ['S1', 'R1', 'T1', 'A3'], 
...  ['S2', 'R2', 'T2', 'A4'], 
...  ['S1', 'R1', 'T1', 'A5'], 
...  ['S2', 'R2', 'T2', 'A6'] 
... ] 

>>> collate(data) 
defaultdict(<type 'list'>, { 
    ('S2', 'R2', 'T2'): ['A4', 'A6'], 
    ('S1', 'R1', 'T1'): ['A3', 'A5'] 
}) 

你可以用这个工作就像你的任何其他词典，例如

>>> for (sender, receiver, text), addresses in collate(data).items(): 
...  print sender, receiver, text 
...  print '|'.join(addresses) 
...  print 
... 
S2 R2 T2 
A4|A6 

S1 R1 T1 
A3|A5