Pie chart color customization in Matplotlib - Step-by-Step Execution

Concept Flow - Pie chart color customization

Start: Prepare data

↓

Choose colors list

↓

Call plt.pie() with colors

↓

Render pie chart with chosen colors

↓

Display chart

The flow shows preparing data, selecting colors, applying them in the pie chart, and displaying the result.

Execution Sample

Matplotlib

import matplotlib.pyplot as plt
sizes = [30, 20, 50]
colors = ['red', 'green', 'blue']
plt.pie(sizes, colors=colors)
plt.show()

This code draws a pie chart with three slices colored red, green, and blue.

Execution Table

Step	Action	Input/Parameter	Effect/Result
1	Prepare data sizes	[30, 20, 50]	Data ready for pie chart
2	Define colors list	['red', 'green', 'blue']	Colors assigned to slices
3	Call plt.pie()	sizes=[30,20,50], colors=['red','green','blue']	Pie chart slices colored accordingly
4	Render pie chart	N/A	Pie chart with red, green, blue slices shown
5	Display chart	plt.show()	Chart window opens with colored pie

💡 All slices colored and chart displayed, execution ends.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
sizes	undefined	[30, 20, 50]	[30, 20, 50]	[30, 20, 50]	[30, 20, 50]
colors	undefined	undefined	['red', 'green', 'blue']	['red', 'green', 'blue']	['red', 'green', 'blue']

Key Moments - 2 Insights

Why do the colors not change if I don't pass the colors parameter?

Without the colors parameter, matplotlib uses default colors. See execution_table step 3 where colors are explicitly passed to change slice colors.

What happens if the colors list length doesn't match the data size?

Matplotlib cycles through colors if fewer colors than slices are given. This is why colors list length should match sizes for clear mapping, as shown in execution_table step 2.

Visual Quiz - 3 Questions

Look at the execution table, what color is assigned to the second slice?

A red

B blue

C green

D default color

💡 Hint

Check the colors list in execution_table step 2 and 3.

At which step is the colors list defined?

A Step 2

B Step 1

C Step 3

D Step 4

💡 Hint

Look at the 'Action' and 'Input/Parameter' columns in execution_table.

If you remove the colors parameter in plt.pie(), what will happen?

A The slices will all be the same color

B Matplotlib will use default colors for slices

C The pie chart will not display

D An error will occur

💡 Hint

Refer to key_moments about default color behavior.

Concept Snapshot

Pie chart color customization in matplotlib:
- Use plt.pie(data, colors=colors_list)
- colors_list must match data length for clear mapping
- If colors not given, default colors apply
- Colors can be named strings or hex codes
- Call plt.show() to display the chart

Full Transcript

This visual execution traces how to customize pie chart colors in matplotlib. First, data sizes are prepared as a list of values. Then, a colors list is defined with color names matching each slice. The plt.pie() function is called with sizes and colors parameters, which applies the colors to each slice in order. Finally, plt.show() displays the pie chart with the chosen colors. Key points include that colors must be passed explicitly to override defaults, and the colors list length should match the data length for clarity. The execution table shows each step and the variable states. The quiz tests understanding of color assignment and parameter usage.