<p>我想您需要<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.sort_values.html" rel="nofollow">^{<cd1>}</a>of <a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.notnull.html" rel="nofollow">^{<cd2>}</a>的<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.sum.html" rel="nofollow">^{<cd3>}</a>,然后得到{<cd4>}的索引。拉丝使用<code>subset</code>:</p>
<pre><code>df1 = df.pivot(index='chemicals', columns='proteins', values='scores')
cols = df1.notnull().sum(axis=0).sort_values(ascending=False).index
print cols
Index([u'10116.ENSRNOP00000003921', u'10116.ENSRNOP00000008952',
u'10116.ENSRNOP00000004027', u'10116.ENSRNOP00000001021'],
dtype='object', name=u'proteins')
print df1[cols]
proteins 10116.ENSRNOP00000003921 10116.ENSRNOP00000008952 \
chemicals
CID000000006 196.0 NaN
CID000000051 246.0 NaN
CID000000085 196.0 NaN
CID000000119 247.0 NaN
CID000000134 NaN 159.0
CID000000135 NaN 157.0
CID000000174 NaN 439.0
CID000000175 NaN NaN
CID000000177 NaN NaN
proteins 10116.ENSRNOP00000004027 10116.ENSRNOP00000001021
chemicals
CID000000006 NaN NaN
CID000000051 NaN NaN
CID000000085 NaN NaN
CID000000119 NaN NaN
CID000000134 NaN NaN
CID000000135 NaN NaN
CID000000174 NaN NaN
CID000000175 NaN 858.0
CID000000177 760.0 NaN
</code></pre>
<p>或<a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.reindex_axis.html" rel="nofollow">^{<cd6>}</a>:</p>
^{pr2}$