IPython Notebook keyboard shortcut search for text
Enter Command Mode by pressing esc, followed by find and replace key binding f, so
esc then f
Take the User Interface Tour (Help Menu) if you haven't already
There is a find-and-replace command in Jupyter. It's key binding is F (command mode):
Of course you can find text with the browser's functionality, (I find it sometimes better), but the command in Jupyter is also very useful. I use a lot that function Replace in selected cells when I copy-paste a bunch of code and then change variables or something like that:
(Note: You can launch the Command Palette with shift+ctrl+P, and browse or run other commands)