In Python, we can use Matplotlib pyplot.savefig function¹ to export graphics, and specify dpi (dots per inch)² of the figure. Take the Matplotlib official example Bar color demo³ as an example:

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# https://matplotlib.org/stable/gallery/lines_bars_and_markers/bar_colors.html#sphx-glr-gallery-lines-bars-and-markers-bar-colors-py

import matplotlib.pyplot as plt

fig, ax = plt.subplots()

fruits = ['apple', 'blueberry', 'cherry', 'orange']
counts = [40, 100, 30, 55]
bar_labels = ['red', 'blue', '_red', 'orange']
bar_colors = ['tab:red', 'tab:blue', 'tab:red', 'tab:orange']

ax.bar(fruits, counts, label=bar_labels, color=bar_colors)

ax.set_ylabel('fruit supply')
ax.set_title('Fruit supply by kind and color')
ax.legend(title='Fruit color')

# Save the figure
plt.savefig("image.png",dpi=300)

# Show the figure
plt.show()

300 dpi (65 KB):

600 dpi (149 KB):

1800 dpi (665 KB):

Compared with the way of directly copying image (in Spyder software) by right clicking on the image and then choosing Copy Image (the result shows as follows), we can get a much clearer image by pyplot.savefig function:

this feature is the same as in MATLAB.

However, it should be noted that, pyplot.savefig should be used BEFORE pyplot.show; if choose the opposite order:

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# ...

# Show the figure
plt.show()

# Save the figure
plt.savefig("image.png",dpi=300)

the exported image is empty:

As described in Matplotlib documentation⁴, this is because pyplot.show function will close the figure:

“If you want an image file as well as a user interface window, use pyplot.savefig before pyplot.show. At the end of (a blocking) show() the figure is closed and thus unregistered from pyplot. Calling pyplot.savefig afterwards would save a new and thus empty figure. This limitation of command order does not apply if the show is non-blocking or if you keep a reference to the figure and use Figure.savefig.”

References