Debugging with nvim-dap

DAP — the Debug Adapter Protocol — is LSP’s sibling: one protocol, per-language adapters (Python’s is debugpy, installed via Mason), any editor.

The keymaps

The course config groups debugging under <leader>d:

Keys	Action
`<leader>db`	toggle a breakpoint on this line
`<leader>dc`	continue / start the session
`<leader>do`	step over one line
`<leader>dt`	terminate the session

Put the cursor on the line where the interesting thing happens and press <leader>db. The line is now a tripwire.
<leader>dc, choose how to launch (for a script: run the current file), and the program runs — then stops right on your line.
The dap-ui panels show every local variable, live: arguments, loop state, the call stack. Step with <leader>do and watch values update.
<leader>dt shuts the session down.

No print statements were harmed. The state you used to reconstruct by logging is simply on screen.