擅长:python、mysql、java
<p>如果数据帧按<code>'Year'</code>排序</p>
<pre><code>df.sort_values('Year', inplace=True)
</code></pre>
<p>然后可以观察<code>pd.Series</code>属性<br/>
<a href="http://pandas.pydata.org/pandas-docs/version/0.19.2/generated/pandas.Series.is_monotonic.html" rel="nofollow noreferrer">^{<cd3>}</a><br/>
<a href="http://pandas.pydata.org/pandas-docs/version/0.19.2/generated/pandas.Series.is_monotonic_decreasing.html" rel="nofollow noreferrer">^{<cd4>}</a><br/>
<a href="http://pandas.pydata.org/pandas-docs/version/0.19.2/generated/pandas.Series.is_monotonic_increasing.html" rel="nofollow noreferrer">^{<cd5>}</a></p>