擅长:python、mysql、java
<p>试试这个:</p>
<pre><code>l = set(i[0] for i in country_city_tuples)
d = {}
for i in l:
d[i] = sum([1 for j in country_city_tuples if j[0]==i])
</code></pre>
<p><strong>输出</strong>:</p>
<pre><code>{'Italy': 2, 'Netherlands': 4, 'Spain': 4}
</code></pre>