擅长:python、mysql、java
<p>将词典理解与<a href="http://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.assign.html" rel="nofollow noreferrer">^{<cd1>}</a>结合使用:</p>
<pre><code>dataframes = {key:val.assign(Key = pd.to_datetime(key.split('_')[1]))
for key, val in dataframes.items()}
</code></pre>
<p>您的代码应该由<code>key</code>更改为select<code>DataFrame</code>:</p>
<pre><code>for key, val in dataframes.items():
dataframes[key]['Key'] = pd.to_datetime(key.split('_')[1])
</code></pre>