Text placement with ax.text in Matplotlib - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this matplotlib text placement code?

Consider the following code that places text on a plot using ax.text. What text will appear at coordinates (0.5, 0.5)?

Matplotlib

import matplotlib.pyplot as plt
fig, ax = plt.subplots()
ax.text(0.5, 0.5, 'Center', ha='center', va='center')
plt.close(fig)
print(ax.texts[0].get_text())

A "ha='center', va='center'"

B "Center"

C "0.5, 0.5"

D "center"

💡 Hint

Look at the third argument of ax.text. It is the string that will be displayed.

The ax.text function places the string given as the third argument at the specified coordinates. Here, the string is "Center".

❓ data_output

intermediate

How many text objects are on the axes after this code?

After running the code below, how many text objects are present on the axes?

Matplotlib

import matplotlib.pyplot as plt
fig, ax = plt.subplots()
ax.text(0.1, 0.1, 'A')
ax.text(0.2, 0.2, 'B')
ax.text(0.3, 0.3, 'C')
plt.close(fig)
print(len(ax.texts))

A 3

B 2

C 1

D 0

💡 Hint

Each call to ax.text adds one text object to the axes.

There are three calls to ax.text, so three text objects are added.

❓ visualization

advanced

Which option shows the correct vertical alignment of text?

Given the code below, which option correctly describes the vertical alignment of the text?

import matplotlib.pyplot as plt
fig, ax = plt.subplots()
ax.text(0.5, 0.5, 'Text', va='top')
plt.close(fig)

A The text is aligned so its top is at y=0.5

B The text is aligned so its bottom is at y=0.5

C The text is aligned so its center is at y=0.5

D The text is aligned so its baseline is at y=0.5

💡 Hint

Vertical alignment va='top' means the top of the text is at the given y coordinate.

Setting va='top' places the top edge of the text at the y coordinate.

🧠 Conceptual

advanced

What happens if you set ha='right' in ax.text?

In matplotlib, what does setting ha='right' do to the text placement?

A The center of the text is placed at the x coordinate

B The left edge of the text is placed at the x coordinate

C The right edge of the text is placed at the x coordinate

D The text is rotated 90 degrees

💡 Hint

Horizontal alignment ha='right' aligns the right edge of the text to the x coordinate.

Setting ha='right' means the text's right edge is at the x coordinate.

🔧 Debug

expert

What error does this code raise?

What error will this code raise?

import matplotlib.pyplot as plt
fig, ax = plt.subplots()
ax.text(0.5, 0.5, 'Hello', ha='middle')
plt.close(fig)

A No error, text is placed with default alignment

B TypeError: text() got an unexpected keyword argument 'ha'

C SyntaxError: invalid syntax

D ValueError: Invalid horizontal alignment

💡 Hint

Check the valid values for ha in matplotlib documentation.

The value 'middle' is not valid for ha. Valid values are 'left', 'center', 'right'.