Pitfalls when working with Jupyter notebooks

You can execute the same cell in Jupyter notebooks multiple times. This may lead to notebooks which make no sense to the reader.

a = 5
b = 5

a = a + 1

a + b

15

You can execute them in the wrong order or overwrite variables, which leads to the same effect.

d = 5

d = 10

d

5

You can see that cells were executed in the wrong order, repeatedly or not subsequently, by reading the number [?] left to the cell.

Tip: When your notebook is ready, click on menu Kernel > Restart & Run all to make sure all cells in the notebook are executed in the right order.