plotly legend

Plotly is a powerful Python library for creating interactive visualizations. Legends in Plotly are used to provide context and identify the different elements in a plot, such as lines, markers, or colors. To add a legend to a Plotly graph, you can use the `legend` attribute within the layout object.

Here's an example of how you can add a legend to a Plotly graph:

import plotly.graph_objects as go

# Create a scatter plot
fig = go.Figure(data=go.Scatter(x=[1, 2, 3], y=[4, 5, 6], name='Data'))

# Set layout properties
fig.update_layout(
    showlegend=True,  # Show legend
    legend=dict(
        x=0,  # Legend position (0-1)
        y=1.0  # Legend position (0-1)
    )
)

# Display the plot
fig.show()

In this example, we create a scatter plot with three data points and assign it a name 'Data'. By setting `showlegend` to `True` in the layout, we enable the display of the legend. The `legend` property allows you to customize its position by specifying `x` and `y` values between 0 and 1.