Adding value labels to hvplot.bar

Question

Using the hvplot tutorial we are trying to generate a bar plot with values as labels on the bars itself.
The bar plot is generated using the following code

import dask.dataframe as dd
import hvplot.pandas
df = dd.read_parquet('data/earthquakes.parq').persist()  
df.magType.value_counts().compute().to_frame().hvplot.bar()

How can we add the value of the bars on the bar itself?

Answer 1

Use holoviews hv.Labels() to add value labels to your data.

You create the labels separately and use the * symbol to overlay your labels on your plot.

Here's a working example:

# import libraries
import numpy as np
import pandas as pd

import holoviews as hv
import hvplot.pandas

# create some sample data
df = pd.DataFrame({
    'col1': ['bar1', 'bar2', 'bar3'],
    'col2': np.random.rand(3)
})

# create your plot
plot = df.hvplot(kind='bar', x='col1', y='col2', ylim=(0, 1.2))

# create your labels separately
# kdims specifies the x and y position of your value label
# vdims specifies the column to use for the value text of your label
labels = hv.Labels(data=df, kdims=['col1', 'col2'], vdims='col2')

# use the * symbol to overlay your labels on your plot
plot * labels

Final result: