擅长:python、mysql、java
<p>使用<code>defaultdict</code>可以轻松实现这种连接:</p>
<pre><code>subs_by_main_id = defaultdict(list)
for entry in list1:
sub_id = entry['subId']
for main_id in entry['mainIds']:
subs_by_main_id[main_id].append(sub_id)
return [{'mainId': main_id, 'subIds': sub_ids}
for main_id, sub_ids in sub_by_main_id.items()]
</code></pre>