Dash Plotly Line Chart: Customize Hover Information with hovertemplate

Dash Plotly Line Chart: Customize Hover Information with hovertemplate

When using hovermode='x unified' in Dash Plotly line charts, you can customize the hover information displayed by leveraging the hovertemplate parameter. This allows for simplifying the hover content by selectively hiding specific values.

Example:

Let's say you want to hide the y-value for data points where the y-value is 0. You can achieve this using a conditional statement within the hovertemplate:

import plotly.graph_objs as go

x = [1, 2, 3, 4, 5]
y = [0, 2, 3, 0, 4]

fig = go.Figure(
    go.Scatter(x=x, y=y, mode='lines+markers',
               hovertemplate='x=%{x}<br>y=%{y:.2f}' if '%{y:.2f}' not in ['0.00', '0'] else 'x=%{x}')
)
fig.update_layout(hovermode='x unified')
fig.show()

In this example, the hovertemplate will display both x and y values. However, if the y-value is 0 or 0.00, only the x-value will be shown. You can modify the conditional statement to control when the y-value is displayed based on your specific needs.

Key Points:

• hovertemplate: Allows you to define the structure and content of the hover information.
• Conditional Statements: Use conditional statements within hovertemplate to control which values are displayed based on specific criteria.
• hovermode='x unified': Ensures that all data points along the same x-value share the same hover information.

By customizing the hovertemplate, you can present more concise and informative hover information in your Dash Plotly line charts.