Saving figures in Data Analysis Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What function is used in Python's matplotlib to save a figure to a file?

The function savefig() is used to save the current figure to a file in matplotlib.

beginner

Which file formats can you save a matplotlib figure as?

You can save figures in formats like PNG, JPG, PDF, SVG, and EPS by specifying the file extension in savefig().

intermediate

How do you save a figure with a transparent background in matplotlib?

Use plt.savefig('filename.png', transparent=True) to save the figure with a transparent background.

intermediate

Why might you want to call plt.close() after saving a figure?

Calling plt.close() frees up memory by closing the figure, especially useful when saving many figures in a loop.

beginner

What does the dpi parameter control in savefig()?

The dpi parameter controls the resolution (dots per inch) of the saved image, affecting its quality and file size.

Which command saves the current matplotlib figure as a PNG file named 'plot.png'?

A plt.savefig('plot.png')

B plt.save('plot.png')

C plt.savefig('plot')

D plt.export('plot.png')

The correct function to save a figure is savefig(), and the filename must include the extension.

What happens if you save a figure without specifying the file extension?

A Matplotlib raises an error

B Matplotlib saves it but the format is unknown

C Matplotlib saves it as a PNG by default

D Matplotlib saves it as a PDF by default

Matplotlib saves it as a PNG by default if no file extension is provided.

How can you save a figure with higher resolution?

A Save as SVG format only

B Increase the figure size only

C Use <code>transparent=True</code>

D Use <code>dpi</code> parameter with a higher value in <code>savefig()</code>

Increasing the dpi value in savefig() increases the image resolution.

Which of these is NOT a valid file format for saving matplotlib figures?

A JPG

B DOCX

C PNG

D SVG

DOCX is a document format, not an image format supported by matplotlib.

Why is it good practice to call plt.close() after saving a figure in a loop?

A To clear the figure and free memory

B To save the figure again

C To display the figure on screen

D To rename the figure

Closing the figure frees memory and prevents too many open figures when saving multiple plots.

Explain how to save a matplotlib figure as a high-quality PNG file with a transparent background.

Think about the parameters you pass to savefig.

Describe why managing figures with plt.close() is important when saving many plots in a script.

Consider what happens if you don't close figures.