擅长:python、mysql、java
<p>有<code>axhline</code>和<code>hlines</code>。简单的例子:</p>
<pre><code>chart = sns.relplot(x="x", y="y", kind="line", data=df)
chart.axes[0][0].axhline(y = 10, color='black', linewidth=2, alpha=.7)
chart.axes[0][0].hlines( y = 20, color='black', linewidth=2, alpha=.7,
xmin = 30, xmax = 50)
</code></pre>
<p>似乎<code>hlines</code>允许minmax(<a href="https://matplotlib.org/3.1.0/api/_as_gen/matplotlib.pyplot.hlines.html" rel="nofollow noreferrer">documentation</a>),但<code>axhline</code>不允许</p>