Prerequisites: Python Plotly
In this article, we will explore how to Hover Text and Formatting in Python.
It is a useful approach to Hover Text and Formatting as it allows to reveal a large amount of data about complex information. One of the most deceptively-powerful features of data visualization is the ability for a viewer to quickly analyze a sufficient amount of information about data when pointing the cursor over the point label appears.
Example 1: Default
The default setting is layout.hovermode=’closest’, wherein a single hover label appears for the point directly underneath the cursor.
Python3
import plotly.express as pxdf = px.data.gapminder().query("continent=='Oceania'")fig = px.line(df, x="year", y="lifeExp", color="country")fig.update_traces(mode="markers+lines")fig.show() |
Output:
Example 2: x unified
If layout.hovermode=’x’ , a single hover label appears per trace, for points at the same x value as the cursor.
Python3
import plotly.express as pxdf = px.data.gapminder().query("continent=='Oceania'")fig = px.line(df, x="year", y="lifeExp", color="country")fig.update_traces(mode="markers+lines", hovertemplate=None)fig.update_layout(hovermode="x unified")fig.show() |
Output:
Example 3: y unified
If layout.hovermode=’y’ , a single hover label appears per trace, for points at the same y value as the cursor.
Python3
import plotly.express as pxdf = px.data.gapminder().query("continent=='Oceania'")fig = px.line(df, x="year", y="lifeExp", color="country")fig.update_traces(mode="markers+lines", hovertemplate=None)fig.update_layout(hovermode="y unified")fig.show() |
Output:
Text Formatting
Example 1: user_defined hovertemplate
GDP: %{x} <br>Life Expectancy: %{y}
Here, GDP and Expectancy is used as naming convention about the data whereas %{ <variable>} which allows to revel a large amount of data about complex information.
Python3
import plotly.express as pxdf_2007 = px.data.gapminder().query("year==2007")fig = px.scatter(df_2007, x="gdpPercap", y="lifeExp", log_x=True, color='continent')fig.update_traces(hovertemplate='GDP: %{x} <br>Life Expectancy: %{y}')fig.show() |
Output:
Example 2: user_defined hovertemplate
%{label}: <br>Popularity: %{percent} </br> %{text}
Here, Label, Percent, and Text is used as naming convention about the data whereas %{ <variable>} which allows to revel a large amount of data about complex information.
Python3
import plotly.graph_objects as gofig = go.Figure(go.Pie( name = "", values = [2, 5, 3, 2.5], labels = ["R", "Python", "Java Script", "Matlab"], text = ["R", "Python", "JS", "Matlab"], hovertemplate = "%{label}: <br>Popularity: %{percent} </br> %{text}"))fig.show() |
Output:
