Creating custom style sheets in Matplotlib - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to apply a custom style sheet named 'mystyle' in matplotlib.

Matplotlib

import matplotlib.pyplot as plt
plt.style.use('[1]')
plt.plot([1, 2, 3], [4, 5, 6])
plt.show()

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

Aseaborn

Bdefault

Cmystyle

Dggplot

Attempts:

3 left

💡 Hint

Common Mistakes

Using a built-in style name instead of the custom one.

Forgetting to put the style name in quotes.

Use plt.style.use('mystyle') to apply the custom style sheet named 'mystyle'.

2fill in blank

medium

Complete the code to save a custom style dictionary to a file named 'mystyle.mplstyle'.

Matplotlib

style_dict = {'lines.linewidth': 2, 'axes.titlesize': 14}
with open('[1]', 'w') as f:
    for key, value in style_dict.items():
        f.write(f"{key}: {value}\n")

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

Astyle.txt

Bconfig.cfg

Cstyle.json

Dmystyle.mplstyle

Attempts:

3 left

💡 Hint

Common Mistakes

Saving the style with a wrong file extension.

Using a filename that matplotlib won't recognize as a style sheet.

The custom style sheet must be saved with the extension .mplstyle for matplotlib to recognize it.

3fill in blank

hard

Fix the error in the code to correctly load a custom style sheet from a file path.

Matplotlib

import matplotlib.pyplot as plt
style_path = '/path/to/[1]'
plt.style.use(style_path)
plt.plot([1, 2], [3, 4])
plt.show()

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

Amystyle.mplstyle

Bstyle.cfg

Cmystyle.txt

Dcustomstyle.json

Attempts:

3 left

💡 Hint

Common Mistakes

Using a file with the wrong extension.

Not providing the full filename including extension.

Matplotlib style sheets must have the .mplstyle extension to be loaded correctly from a file path.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that sets line width to 3 for all keys starting with 'lines.'.

Matplotlib

style_dict = {key: [1] for key in keys if key.[2]('lines.')}

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

A3

Bstartswith

Cin

Dendswith

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'in' instead of 'startswith' for filtering keys.

Setting the wrong value for line width.

Use 3 as the value for line width and startswith to filter keys starting with 'lines.'.

5fill in blank

hard

Fill all three blanks to create a style dictionary that sets font size to 12 for axes titles, font family to 'serif', and line color to 'red'.

Matplotlib

style_dict = {
    'axes.titlesize': [1],
    'font.family': [2],
    'lines.color': [3]
}

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

A12

B'serif'

C'red'

D'12pt'

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around numbers incorrectly.

Forgetting quotes around string values.

Set axes.titlesize to 12, font.family to 'serif', and lines.color to 'red' in the style dictionary.

Practice

1. What is the main purpose of creating a custom style sheet in matplotlib?

easy

A. To make charts look consistent and save time when plotting

B. To write Python code faster

C. To change the data in the plot

D. To export plots as images

Solution

1. Step 1: Understand the role of style sheets

   Style sheets control the appearance of plots, such as colors and fonts.

2. Step 2: Identify the benefit of custom style sheets

   Custom style sheets help keep charts consistent and save time by reusing styles.

3. Final Answer:

   To make charts look consistent and save time when plotting -> Option A

4. Quick Check:

   Custom style sheets = consistent charts + time saving [OK]

Hint: Custom styles = consistent look + less work [OK]

Common Mistakes:

• Thinking style sheets change data
• Confusing style sheets with exporting images
• Believing style sheets speed up coding

2. Which of the following is the correct way to apply a custom style sheet named my_style.mplstyle in matplotlib?

easy

A. plt.style('my_style')

B. plt.use_style('my_style')

C. plt.style.use('my_style.mplstyle')

D. plt.style.apply('my_style.mplstyle')

Solution

1. Step 1: Recall the correct function to apply styles

   The function to apply a style sheet is plt.style.use().

2. Step 2: Check the correct argument format

   The style file name should be passed as a string, including the extension if needed.

3. Final Answer:

   plt.style.use('my_style.mplstyle') -> Option C

4. Quick Check:

   Use plt.style.use() with filename [OK]

Hint: Use plt.style.use('filename') to apply styles [OK]

Common Mistakes:

• Using incorrect function names like plt.use_style
• Omitting .mplstyle extension when needed
• Using plt.style() instead of plt.style.use()

3. Given the following code, what will be the color of the line in the plot?

import matplotlib.pyplot as plt
plt.style.use('custom_style.mplstyle')
plt.plot([1, 2, 3], [4, 5, 6])
plt.show()

Assuming custom_style.mplstyle contains:

lines.color: red

medium

A. Black

B. Blue

C. Green

D. Red

Solution

1. Step 1: Understand style sheet effect

   The style sheet sets lines.color to red, which changes line color.

2. Step 2: Apply style to plot

   Since plt.style.use('custom_style.mplstyle') is called, the line color becomes red.

3. Final Answer:

   Red -> Option D

4. Quick Check:

   Style sets lines.color = red, so line is red [OK]

Hint: Style file sets line color, so plot uses that color [OK]

Common Mistakes:

• Ignoring style file and expecting default color
• Confusing color names
• Not applying style before plotting

4. What is wrong with this code snippet if the custom style sheet my_style.mplstyle is not applied?

import matplotlib.pyplot as plt
plt.style.use(my_style.mplstyle)
plt.plot([1, 2], [3, 4])
plt.show()

medium

A. The style file name should be a string in quotes

B. plt.plot() is missing required arguments

C. plt.show() should be called before plt.plot()

D. The style file must be imported as a module

Solution

1. Step 1: Check how style file is passed

   The style file name must be a string, so it needs quotes around it.

2. Step 2: Identify the error in code

   Without quotes, Python treats my_style.mplstyle as a variable, causing an error.

3. Final Answer:

   The style file name should be a string in quotes -> Option A

4. Quick Check:

   File name must be string in plt.style.use() [OK]

Hint: Put style file name in quotes inside plt.style.use() [OK]

Common Mistakes:

• Forgetting quotes around style file name
• Calling plt.show() too early
• Trying to import style file as Python module

5. You want to create a custom style sheet that sets the plot background to light gray and the grid lines to dashed blue. Which of the following .mplstyle file contents will achieve this?

hard

A. figure.facecolor: #d3d3d3
grid.color: blue
grid.linestyle: '--'

B. axes.facecolor: lightgray
grid.color: blue
grid.linestyle: '--'

C. background.color: lightgray
grid.color: blue
grid.line: dashed

D. axes.background: lightgray
grid.style: dashed
grid.color: blue

Solution

1. Step 1: Identify correct keys for background and grid

   The correct key for plot background is axes.facecolor. Grid color uses grid.color and line style uses grid.linestyle.

2. Step 2: Match values to keys

   Light gray is 'lightgray', grid color is 'blue', and dashed lines use '--'. axes.facecolor: lightgray grid.color: blue grid.linestyle: '--' matches all correctly.

3. Final Answer:

   axes.facecolor: lightgray grid.color: blue grid.linestyle: '--' -> Option B

4. Quick Check:

   Use axes.facecolor and grid.linestyle for background and grid [OK]

Hint: Use axes.facecolor and grid.linestyle keys in style file [OK]

Common Mistakes:

• Using wrong keys like axes.background or grid.style
• Wrong color names or formats
• Missing quotes or incorrect line style syntax