Working with Other Files

We are going to talk about what to do when you have a function in one Jupyter notebook, but you want to use it in another jupyter notebook.

Let’s take this exponent_a_list function we’ve seen previously that creates a new list containing the exponent values of the input list.

We are using this function inside our notebook called exponents.ipynb.

Let’s remind ourselves how it works.

First, we run the cell to put the function into Python’s memory, and we take some tests that we wrote earlier and run them to make sure our function still works.

We then execute the cell that calls the function on a list containing the values 2, 3, and 4 and get the output.

Let’s say we want to create a new jupyter notebook.

We then named it more-exp-calc.ipynb.

If we call the function exponent_a list with the values 1, 3, and 5 inside of this notebook, it will result in an error because exponent a list doesn’t exist in this workspace.

What can we do to solve this problem?

One thing we could do is copy and paste the function into this notebook.

This would be annoying to do that every single time that we want to use this function.

Instead, we can create a python script and put the function inside that.

Then for each notebook that needs this function, we can import it similarly to how we imported packages like pandas or Altair.

Let’s create a text file and rename it exponent_a_list, and instead of an ending of .txt, we’re going to end it with .py.

Inside of this python script exponent_a_list.py, we’re going to copy the original function and save this file.

Next, we can go into our more-exp-calc.ipynb notebook, and in a new cell at the top, we write a statement that will tell Python where the exponent_a_list function is located and bring it into the notebook environment.

We write

from exponent_a_list import exponent_a_list

You may wonder why we write exponent_a_list twice; well, the exponent_a_list is referencing the name of this python script file that we just created, so whatever we name this file is what we put after the from statement.

The second exponent_a_list of our statement is telling us what function would like to import from that file.

We only have one function in the file exponent_a_list.py, but you can have multiple functions that could live in this file.

We can now run the cell containing the import statement followed by the function exponent_a list for values 1, 3, and 5.

This time instead of an error, we get the expected results.

We can go back to our original notebook exponent.ipynb and replace the function we had written with that import statement.

This now gives us the ability to run all of the cells in this notebook the way we just did in the other notebook more-exp-calc.ipynb.

Let’s apply what we learned!