Preparations¶
Upgrade to Polars
Aarla Frij opened the hatch to her submarine, swiftly slided down the ladder to the cockpit and cuddled comfortably into the captains seat. A new expedition into the depths of the seven oceans awaited her. A new adventure. What secrets were waiting out there? A soft hum from the energy supply was the only sound in the cockpit. The ship was still asleep.
"I still have time for a nap before the mission," Aarla thought.
Suddenly another bear came whistling into the cockpit, balancing tea cups on a tablet. That was Ming Ming, the intern from the remote world of Pandalor. Aarla sighed.. no nap.
"Hello captain! I've been down here for a while already. The ship is all right, but I think the computer needs a software update? Can you show me how to do this? Pleeease."
Aarla turned to the right and started searching through a pile of notes.
"Hm, somewhere here should be the ships instructions," Aarla muttered as she continued her search.
Finally, she pulled out a worn handbook.
"OK, let's turn this thing on!".
Install Python¶
Before you can start your journey, you need to install a few programs on your ships' computer.
First, you need to install a Python distribution that allows you to run the Jupyter Notebook format. Anaconda is a one-stop installation that contains all necessary Python packages and an editing environment.
Go to www.anaconda.com and download Anaconda for your system (the free version) and follow the installation instructions.
Can I use the standard Python installation?
Yes. The version from www.python.org <https://www.python.org> works fine. While Anaconda is easier to get started with, many professional developers prefer the slimmer standard Python installation.
Can I use VSCode instead?
Yes. VSCode has a great plugin that handles the interactive Python environment. It is very similar to Jupyter. However, I am not using it so please don't ask me for configuration details.
Can I use Google Colab?
Yes. Google Colab is free and completely cloud-based. When using Colab, most of the Python libraries you will need are already installed. However, uploading files will be a bit more tedious. Please look up how to do that.
Can I install packages on my own?
Yes. This is a good idea if you already have a Python distribution installed on your system. You need to install a few core libraries. Use the pip program from a terminal to install the latest version of everything:
pip install --upgrade polars numpy seaborn matplotlib
Start Jupyter¶
from the Anaconda Navigator, start the Jupyter Notebook.
Jupyter will run as a HTTP server in the background
From the overview page, create a new Python3 notebook with the button New (top-right)
Write an import section¶
Check if the core Python libraries for data analytics are installed. Write into an empty code cell:
import polars as pl
import numpy as np
import seaborn as sns
from matplotlib import pyplot as plt
Execute the command with the triangular "play" button in the toolbar or press Shift-Enter. You should see an empty output and a new input cell. If you don't see an error message, everything has worked.
Keyboard shortcuts¶
Hitting those small keys with your big paws is not easy. It takes years of practice. To make your life easier, there are a couple of useful shortcuts:
key |
description |
|---|---|
Shift + Enter |
execute a cell |
Escape + A |
insert a cell above |
Escape + B |
insert a cell below |
Escape + X |
delete the current cell |
Tab |
autocomplete names |
Shift + Tab |
context-sensitive help |
Edit Markdown¶
Edit and format a Markdown cell in Jupyter
### Captains log, stardate <ENTER_TODAYS_DATE>
**Captain <YOUR NAME>** has taken command of the ship *<NAME YOUR SHIP>*.
Change the type of the cell to Markdown using the icons or press Escape + M.
Execute the code with the play button on top or press Shift + Enter. You should see the paragraph formatted as HTML.
Execute Python Code¶
Write a simple Python command. Insert a new cell. Then, run the command to switch on all systems:
print("power up submarine")
Execute the code with the play button on top or press Shift + Enter. Your computer should respond with:
power up submarine
It seems your ships computer is fully online. Time to do some more serious stuff.