擅长:python、mysql、java
<p>这里有一个方法<code>reindex</code>在<code>set_index</code>之后</p>
<pre><code>Locations = [('London','Uk'), ('Paris', 'US'), ('Toronto', 'Canada')]
out = df.set_index(['City','Country']).reindex(Locations).reset_index()
out
Out[83]:
City Country value
0 London Uk NaN
1 Paris US 100
2 Toronto Canada 40
</code></pre>