How to disable line wrapping in Jupyter notebook output cells?

I was able to solve this problem by adding a simple CSS rule to the custom/custom.css file in my Jupyter user configuration:

/*Disable code output line wrapping*/
div.output_area pre {
    white-space: pre;
}

The result:

The div.output_area pre selects the pre preformated text areas of the code output areas for the rule (set of css properties). The white-space property states how the browser should display white spaces in the selected HTML elements with the pre value the browser only breaks at new line characters \n and <br> elements.

This CSS renders well (with a fine horizontal scrollbar) for my Firefox v70.0 and Chorme v78.0.3904.97, according to Can I Use the white-space: pre property and value should work on all modern desktop browsers.

You can find out where your configuration resides by running the following shell command:

jupyter --config

If you want make further style modifications just play around with the inspector of your favorite browser on Jupyter Notebook tab. where you can modify the CSS without permanent effects.

I can't comment so I have to answer: maybe there's something different with the last versions of Jupyter. If the accepted answer doesn't work, you can try with "jp-OutputArea-output" instead of "div.output_area"; for example

from IPython.core.display import display, HTML
display(HTML("<style>div.jp-OutputArea-output pre {white-space: pre;}</style>"))

And if you have a dark-mode browser and you don't like the resulting lighter scrollbars, you can try to set the dark mode in Jupyter adding

display(HTML("<style>:root {color-scheme: dark;}</style>"))

See: How do I switch to Chromes dark scrollbar like GitHub does?

You can use an html magic command. Check the CSS selector is correct, by inspecting the output cell, then edit the below accordingly.

%%html
<style>
div.output_area pre {
    white-space: pre;
}
</style>

If you don't want to mess around with a config file, you can modify the behaviour of a notebook ad hoc by calling the IPython.core.display function. Then add the CSS suggested by @atevm:

from IPython.core.display import display, HTML
display(HTML("<style>div.output_area pre {white-space: pre;}</style>"))

for line in range(5):
    for num in range(70):
        print(f" {num}", end="")
    print()