如何將列表列表轉換為相對頻率字典？

Question

我有一個列表列表，我想將其轉換為相對頻率字典。

列表列表：

[['SBS1', 'SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d'],
 ['SBS1', 'SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d'],
 ['SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d'],
 ['SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d', 'SBS38'],
 ['SBS1', 'SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d']]

列表列表的相對頻率字典

{['SBS1', 'SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d']: 0.6,
 ['SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d']: 0.2,
 ['SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d', 'SBS38']: 0.2}

我怎樣才能做到這一點？

Answer 1

您需要使用元組而不是列表將它們用作字典鍵（鍵需要是可散列的），但如果這不是問題，您可以使用collections.counter來應對變化，然后是字典理解：

from collections import Counter

l = [['SBS1', 'SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d'],
     ['SBS1', 'SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d'],
     ['SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d'],
     ['SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d', 'SBS38'],
     ['SBS1', 'SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d']]

counts = Counter(map(tuple,l))
result = {k:count/len(l) for k, count in counts.items()}

結果：

{('SBS1', 'SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d'): 0.6,
 ('SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d'): 0.2,
 ('SBS5', 'SBS7a', 'SBS7b', 'SBS7c', 'SBS7d', 'SBS38'): 0.2}