擅长:python、mysql、java
<p>正如@phillipcloud指出的,<code>loc</code>更适合这份工作。如果将键指定为元组,也可以设置多个索引集。在</p>
<pre><code>In [2]: mi = DataFrame(dict(
A = np.arange(5).astype(np.float64),
B = np.arange(5).astype(np.int64)),
index=MultiIndex.from_tuples(tuple(zip(*[['bar','bar','baz','baz','baz'],['one','two','one','two','three']])),names=['first','second']))
In [3]: mi
Out[3]:
A B
first second
bar one 0 0
two 1 1
baz one 2 2
two 3 3
three 4 4
In [4]: mi.loc[('baz','two'),'B'] = -5
In [5]: mi
Out[5]:
A B
first second
bar one 0 0
two 1 1
baz one 2 2
two 3 -5
three 4 4
</code></pre>