擅长:python、mysql、java
<p>您可以使用下面给出的代码,它在jsonb中遍历数组并计数键</p>
<pre><code>a =[['sam', '2019-10-11'], ['ram', '2019-10-12'], ['king', '2019-10-11'],
['queen', '2019-10-10'], ['ram', '2019-10-12'], ['kumar', '2019-10-11'],
['jeba', '2019-10-11'], ['sam', '2019-10-10'], ['sam', '2019-10-11'],
['howl', '2019-10-14']]
b = {}
for iter in a:
if iter[1] in b:
if(iter[0] not in b[iter[1]]):
b[iter[1]][iter[0]] = 1
else:
b[iter[1]] = {iter[0]: 1}
print(b)
</code></pre>
<p>上述代码的结果将是:</p>
<pre><code>{'2019-10-11': {'sam': 1, 'king': 1, 'kumar': 1, 'jeba': 1}, '2019-10-12': {'ram': 1}, '2019-10-10': {'queen': 1, 'sam': 1}, '2019-10-14': {'howl': 1}}
</code></pre>
<p>当然你可以像这样把它转换成数组结构</p>
<pre><code>for key in b:
print(key, len(b[key]))
res[0].append(key)
res[1].append(len(b[key]))
</code></pre>
<p>结果是</p>
<pre><code>[['2019-10-11', '2019-10-12', '2019-10-10', '2019-10-14'], [4, 1, 2, 1]]
</code></pre>