擅长:python、mysql、java
<p>这将为您提供预期的输出:</p>
<p><code>df[df.Timestamp.dt.date == pd.to_datetime('2018-01-02')]</code></p>
<p>为了回答您的扩展问题,在末尾添加<code>shape[0]</code>将告诉您子集中有多少行。你知道吗</p>
<p><code>df[df.Timestamp.dt.date == pd.to_datetime('2018-01-02')].shape[0]</code></p>
<p>要添加多个条件:</p>
<p><code>df[(df.Timestamp.dt.date == pd.to_datetime('2018-01-02')) & (df.Group_Id == 52)]</code></p>
<p>这是假设组\u Id是int,否则:</p>
<p><code>df[(df.Timestamp.dt.date == pd.to_datetime('2018-01-02')) & (df.Group_Id == '52')]</code></p>