Donut chart variation in Matplotlib - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a basic pie chart using matplotlib.

Matplotlib

import matplotlib.pyplot as plt

sizes = [30, 20, 50]
labels = ['A', 'B', 'C']

plt.pie(sizes, labels=[1])
plt.show()

Drag options to blanks, or click blank then click option'

Asizes

Bcolors

Clabels

Dexplode

Attempts:

3 left

💡 Hint

Common Mistakes

Using sizes instead of labels for the labels parameter.

Passing a variable that does not exist.

The labels parameter is used to add labels to each slice of the pie chart.

2fill in blank

medium

Complete the code to add a white circle in the center to create a donut chart effect.

Matplotlib

import matplotlib.pyplot as plt

sizes = [40, 35, 25]
labels = ['X', 'Y', 'Z']

plt.pie(sizes, labels=labels)
centre_circle = plt.Circle((0,0), [1], fc='white')
fig = plt.gcf()
fig.gca().add_artist(centre_circle)
plt.show()

Drag options to blanks, or click blank then click option'

A1.5

B0.5

C0

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using a radius equal or greater than 1 which covers the whole pie.

Using zero radius which makes no hole.

The radius of the white circle should be less than 1 to create the donut hole effect. 0.5 is a common choice.

3fill in blank

hard

Fix the error in the code to correctly display the donut chart with percentage labels.

Matplotlib

import matplotlib.pyplot as plt

sizes = [25, 50, 25]
labels = ['Red', 'Green', 'Blue']

plt.pie(sizes, labels=labels, autopct=[1])
centre_circle = plt.Circle((0,0), 0.6, fc='white')
fig = plt.gcf()
fig.gca().add_artist(centre_circle)
plt.show()

Drag options to blanks, or click blank then click option'

A'%1.1f%%'

BNone

C'%.1f%'

D'%1.f%%'

Attempts:

3 left

💡 Hint

Common Mistakes

Using '%1.f%%' which misses the decimal place.

Using '%.1f%' which misses the second percent sign.

The autopct string '%1.1f%%' formats the percentage with one decimal place and a percent sign.

4fill in blank

hard

Fill both blanks to create a donut chart with exploded slices and a shadow effect.

Matplotlib

import matplotlib.pyplot as plt

sizes = [15, 30, 55]
labels = ['Apple', 'Banana', 'Cherry']
explode = ([1], 0, 0)

plt.pie(sizes, labels=labels, explode=explode, shadow=[2])
centre_circle = plt.Circle((0,0), 0.7, fc='white')
fig = plt.gcf()
fig.gca().add_artist(centre_circle)
plt.show()

Drag options to blanks, or click blank then click option'

A0.1

BTrue

CFalse

D0.5

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 instead of a positive float for explode.

Setting shadow to a string instead of a boolean.

Exploding the first slice by 0.1 separates it slightly. Setting shadow to True adds a shadow effect.

5fill in blank

hard

Fill all three blanks to create a donut chart with custom colors, start angle, and percentage format.

Matplotlib

import matplotlib.pyplot as plt

sizes = [20, 40, 40]
labels = ['East', 'West', 'North']
colors = ['#ff9999', '#66b3ff', [1]]

plt.pie(sizes, labels=labels, colors=colors, startangle=[2], autopct=[3])
centre_circle = plt.Circle((0,0), 0.5, fc='white')
fig = plt.gcf()
fig.gca().add_artist(centre_circle)
plt.show()

Drag options to blanks, or click blank then click option'

A'#99ff99'

B90

C'%1.0f%%'

D'#333333'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a color string without quotes.

Using a start angle as a string instead of an integer.

Using autopct without the double percent signs.

The third color is a light green '#99ff99'. The start angle 90 rotates the chart. The autopct '%1.0f%%' shows percentages with no decimals.

Practice

1.

What is the main difference between a donut chart and a pie chart in matplotlib?

easy

A. A donut chart has a hole in the center, a pie chart does not.

B. A donut chart uses bars, a pie chart uses slices.

C. A donut chart shows data over time, a pie chart shows categories.

D. A donut chart is 3D, a pie chart is 2D.

Solution

1. Step 1: Understand pie chart basics

   A pie chart divides a circle into slices representing parts of a whole.

2. Step 2: Identify donut chart feature

   A donut chart is a pie chart with a hole in the center, making it look like a donut.

3. Final Answer:

   A donut chart has a hole in the center, a pie chart does not. -> Option A

4. Quick Check:

   Donut chart = pie chart + hole [OK]

Hint: Donut chart = pie chart with center hole [OK]

Common Mistakes:

• Thinking donut charts use bars
• Confusing donut charts with 3D charts
• Believing donut charts show time series

2.

Which matplotlib code snippet correctly creates a donut chart with a hole size controlled by wedgeprops?

import matplotlib.pyplot as plt
sizes = [30, 40, 30]
plt.pie(sizes, wedgeprops=???)
plt.show()

easy

A. wedgeprops={'height': 0.5}

B. wedgeprops={'radius': 0.5}

C. wedgeprops={'width': 0.5}

D. wedgeprops={'size': 0.5}

Solution

1. Step 1: Recall donut hole control

   The hole size in a donut chart is set by the 'width' key inside wedgeprops.

2. Step 2: Match correct syntax

   Using wedgeprops={'width': 0.5} creates a hole half the radius size.

3. Final Answer:

   wedgeprops={'width': 0.5} -> Option C

4. Quick Check:

   wedgeprops width controls hole size [OK]

Hint: Use wedgeprops={'width': value} for donut hole [OK]

Common Mistakes:

• Using 'radius' instead of 'width'
• Using 'height' or 'size' keys incorrectly
• Omitting wedgeprops entirely

3.

What will be the visual output of this code?

import matplotlib.pyplot as plt
sizes = [10, 20, 30]
plt.pie(sizes, wedgeprops={'width': 0.3})
plt.show()

medium

A. A donut chart with a thin ring shape

B. A pie chart with no hole in the center

C. A donut chart with a very large hole

D. A bar chart instead of a pie chart

Solution

1. Step 1: Analyze wedgeprops width value

   The width is set to 0.3, meaning the donut hole is 70% of the radius.

2. Step 2: Visualize the chart shape

   This creates a donut chart with a thin ring shape because the hole is large but not full radius.

3. Final Answer:

   A donut chart with a thin ring shape -> Option A

4. Quick Check:

   width=0.3 means thin donut ring [OK]

Hint: Smaller width = thinner donut ring [OK]

Common Mistakes:

• Thinking width=0.3 means no hole
• Confusing hole size with radius
• Expecting a bar chart output

4.

Identify the error in this donut chart code and select the fix:

import matplotlib.pyplot as plt
sizes = [25, 35, 40]
plt.pie(sizes, wedgeprops={'width': '0.5'})
plt.show()

medium

A. Add labels parameter

B. Remove wedgeprops entirely

C. Change 'width' to 'radius'

D. Change '0.5' to 0.5 (string to float)

Solution

1. Step 1: Check wedgeprops value type

   The width value is given as a string '0.5', but it must be a number (float).

2. Step 2: Correct the data type

   Changing '0.5' to 0.5 fixes the type error and creates the donut hole properly.

3. Final Answer:

   Change '0.5' to 0.5 (string to float) -> Option D

4. Quick Check:

   width must be float, not string [OK]

Hint: Use numbers, not strings, for wedgeprops values [OK]

Common Mistakes:

• Using string instead of float for width
• Changing width key incorrectly
• Ignoring type errors

5.

You want to create a donut chart showing sales distribution with a hole size that leaves 40% thickness for the slices. Which wedgeprops value should you use?

hard

A. wedgeprops={'width': 0.4}

B. wedgeprops={'width': 0.6}

C. wedgeprops={'width': 0.2}

D. wedgeprops={'width': 1.0}

Solution

1. Step 1: Understand width meaning

   The 'width' value is the thickness of the slices as a fraction of the radius.

2. Step 2: Calculate width for 40% thickness

   For 40% thickness for the slices, set width=0.6 (leaving a hole size of 40%).

3. Final Answer:

   wedgeprops={'width': 0.6} -> Option B

4. Quick Check:

   width=0.6 gives 40% slice thickness [OK]

Hint: Width = slice thickness fraction (1 - hole size) [OK]

Common Mistakes:

• Confusing width with hole size
• Using width less than hole thickness
• Setting width to 1 (no hole)