Python Plotly - 向箱线图添加水平线

Question

我试图在下面的 y=20 处向图中添加水平线，但没有成功。

感谢您的帮助!

import plotly.express as px
tips = px.data.tips()
fig = px.box(tips, x="time", y="total_bill")
fig.show()

Answer 1

如果您想添加一条完全覆盖整个 x 轴的水平线，您可以使用隐藏轴技巧(受 this post 启发):

import plotly.express as px
import plotly.graph_objects as go
tips = px.data.tips()
fig = px.box(tips, x="time", y="total_bill")

# add a second axis that overlays the existing one
fig.layout.xaxis2 = go.layout.XAxis(overlaying='x', range=[0, 2], showticklabels=False)
fig.add_scatter(x = [0, 2], y = [20, 20], mode='lines', xaxis='x2',
                            showlegend=False, line=dict(dash='dash', color = "firebrick", width = 2))

fig.show()

因此，输出图形将如下所示: