Bar Charts

A bar chart is a visual graph that uses rectangular bars to compare the size of different categories. The BarChart module allows you to generate visualizations from dictionaries mapping strings to numerical values.

Create a simple Bar Chart

Let's first prepare the data and label formatting before initializing a simple chart using it.

# Define the chart title
chart_title = "Coffee Grinder Prices"

# Define the chart data
coffee_grinder_prices = {
    "Manual": 29,
    "Blade": 45,
    "Burr":  120,
}

# Custom formatters can override default label values
def custom_label_formatter(_category: str, value: int) -> str:
    return f"{value} $"

# Create the chart object
chart = BarChart(
    coffee_grinder_prices,
    title=chart_title,
    inside_label_formatter=custom_label_formatter,
)

There are a number of configuration parameters available to fine-tune the layout and appearance of the BarChart, which can be passed as keyword arguments.

Parameter	Effect	Default
position	Top-left chart origin as (x, y)	(0, 0)
show_axis	Toggles axis and tick display	False
bar_width	Width of each bar	40
bar_spacing	Horizontal spacing between bars	20
max_bar_height	Height of the tallest bar	200
bar_colors	List of colors or ColorSchemes applied to bars	["#66ccff"]
title	Optional chart title	None
title_text_format	Text formatting for the title	TextFormat()
base_text_format	Formatting for labels below bars	TextFormat()
inside_text_format	Formatting for labels rendered inside bars	TextFormat()
background_color	Optional background rectangle behind the chart	None
axis_tick_count	Number of tick intervals on the chart axis	5
axis_text_format	Formatting for axis tick labels	TextFormat()
base_label_formatter	Callable that formats the category label below each bar	lambda l,v: l
inside_label_formatter	Callable that formats values printed inside each bar	lambda l,v: str(v)
glass	Whether bars have a glass effect.	False
rounded	Whether bars have rounded corners.	False

With a few visual adjustments, the resulting chart renders as: