擅长:python、mysql、java
<p>你可以用</p>
<pre><code>countries_df = pd.DataFrame(continentDict.items(), columns=('country', 'continent'))
countries_df.groupby('continent').count()
</code></pre>
<pre><code> country
continent
Asia 5
Australia 1
Europe 6
North America 2
South America 1
</code></pre>