<p>我正在尝试删除<code>nan</code>,但无法在合并<code>DataFrame</code>的两列时删除</p>
<p>数据如下:</p>
<pre><code>feedback_id _id
568a8c25cac4991645c287ac nan
568df45b177e30c6487d3603 nan
nan 568df434832b090048f34974
nan 568cd22e9e82dfc166d7dff1
568df3f0832b090048f34711 nan
nan 568e5a38b4a797c664143dda
</code></pre>
<p>我想:</p>
<pre><code>feedback_request_id
568a8c25cac4991645c287ac
568df45b177e30c6487d3603
568df434832b090048f34974
568cd22e9e82dfc166d7dff1
568df3f0832b090048f34711
568e5a38b4a797c664143dda
</code></pre>
<p>这是我的密码:</p>
<pre><code>df3['feedback_request_id'] = ('' if df3['_id'].empty else df3['_id'].map(str)) + ('' if df3['feedback_id'].empty else df3['feedback_id'].map(str))
</code></pre>
<p>我得到的输出:</p>
<pre><code>feedback_request_id
568a8c25cac4991645c287acnan
568df45b177e30c6487d3603nan
nan568df434832b090048f34974
nan568cd22e9e82dfc166d7dff1
568df3f0832b090048f34711nan
nan568e5a38b4a797c664143dda
</code></pre>
<p>我也试过这样做:</p>
<pre><code>df3['feedback_request_id'] = ('' if df3['_id']=='nan' else df3['_id'].map(str)) + ('' if df3['feedback_id']=='nan' else df3['feedback_id'].map(str))
</code></pre>
<p>但它给出了一个错误:</p>
<pre><code>ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().
</code></pre>