5 Jupyter Notebooks
A Jupyter Notebook is a file with the extension .ipynb that combines code, its output, and markdown into an interactive notebook-like experience.
5.1 Comparison with Python Scripts
A key difference is that notebooks are interactive, whereas scripts simply run from start to end. Generally, notebooks are more useful for exploratory or visual workflows (e.g. making plots, or analyzing data). It’s also a great tool for learning Python.
5.2 Terminology
The following are fundamental concepts of Jupyter Notebooks:
- Cell
- A Jupyter Notebook is a collection of cells.
- Code Cell
- A cell containing Python code, whose output shows below after execution.
- Cell Output
- The output after executing a cell, which could be many things (e.g. a number, plot, or table)
- Markdown Cell
- A cell containing markdown for nicely formatted text.
- Kernel
- Responsible for executing cells. Same as Python virtual environment for the purposes of this course.
5.3 Running a Jupyter Notebook
The Python extension for VS Code allows opening jupyter notebook files (.ipynb).
Upon opening a notebook, all cells are displayed along with any saved output of those cells.
Running a notebook first requires selecting the kernel (i.e. the Python virtual environment). If the virtual environment has not installed the package ipykernel, then VS Code will ask to do that. Alternatively, manually install it via:
uv pip install ipykernelNext, “Run All” to run all cells from top to bottom. It’s also possible to run (or re-run) cells individually in any order.
It’s good practice to organize notebooks such that they run from top to bottom.
5.4 Creating a Jupyter Notebook
Create a Jupyter Notebook from within VS Code by opening the Command Palette (CTRL + SHIFT + P) and typing “Create: New Jupyter Notebook”.
Save the notebook in a project folder to help VS Code automatically find the project’s virtual environment. Then, start adding and running cells.
5.5 Useful Keyboard Shortcuts
There’s a few useful keyboard shortcuts when working with notebooks:
- Shift + Enter: Run the current cell and move to the next.
- Ctrl + Enter: Run the current cell.
- A: Insert a new cell above.
- B: Insert a new cell below.
5.6 Additional resources
For additional information, refer to VS Code’s documentation on jupyter notebooks.