ipython笔记本“运行所有单元格”是同时执行还是按顺序执行？

Question

I have a code that is applying changes to a dataset and then the next cell picks this up to continue with an other set of changes. This is done for my own readability and troubleshooting in datamunging.

I think I finished the code and want to apply it to the initial data. Ipython notebook has an option run all cells.

My question is does it run them one after another or simultaneously ?

Answer 1

It runs in sequence. You will actually see the progress as the cells that are in queue will show a star In [*]: , while the cells that have successfully will show some number, ex.: In [123] .

Answer 2

It is very easy to see that it runs the cells sequentially. Simply change one cell to have something like

i = 39882

and in the following cell place

print i

If the cells would run concurrently, the latter cell would not print the value modified in the previous cell.