I deleted a Jupyter notebook and when I look in my Files listing it is back again. What happened?

Things that can cause a deleted notebook to reappear:

1. If a notebook is deleted while there is a tab open on it, then any action that triggers saving the notebook will bring it back.
2. If a notebook is closed without halting, its python process will continue to run. That process could trigger a save of the file, bringing it back after deletion.
3. If a notebook is closed and halted, reopening it by clicking in the project log will bring the file back.

How to prevent deleted notebooks from reappearing:

1. After you are finished working with a notebook, click Close and halt. This has the added benefit of freeing up memory.
2. Before deleting a notebook, make sure there are no tabs open running it.