Installing Atom

All Platforms Atom Editor

You won't need the Atom Editor right away. We won't use it until the third week of class.

To install Atom, click the button above to take you to the Atom website. You should see a yellow "Download" button, which has your computer system's OS information above it. Click on that button.

If you are using a Windows computer, the downloaded file will be an .exe file. Double click it and Atom should install automatically. For Linux computers, install the .deb file and then double click on it. You should then be able to install it using your package manager.

If you are using a Mac computer, the downloaded file should be a .zip. Double click on that .zip file, and then drag the resulting Atom.app to your applications folder. The first time you attempt to open it, it may warn that it is an unverified application from the internet. Ignore this and click open on the window that pops up.

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Configuring Preferences

One of the most controversial aspects of Python is that it treats spaces and tabs very differently. If you accidentally put a tab in your program, it will cause your program will crash. And you will have a hard time finding it because both tabs and spaces look exactly the same.

Most of the time, this is not a problem. However, we must first configure Atom so that indentation is consistent across all of our files. First, open Atom. Then, open the Settings menu option; in Windows, it is under the File category, and in Mac, it is under Atom (and is named Preferences). Then, in the settings window that opens, select the Editor category, and scroll down. First, check the boxes "Show Indent Guide" and "Show Invisibles" so that your settings match this image:

Click for Bigger Image

This will allow you to see both tabs and spaces, and to tell the difference between both. Spaces will look like light dots which are centered vertically on each line. Tabs will look like two '>' characters next to each other. These are illustrated in the examples below.

Atom with Tabs (Bad)		Spaces Only (Good)

Continue scrolling down. Change the value in "Tab Length" to 4, and click on the value in "Tab Type". This should open a drop-down menu. Select "soft". This will make Atom automatically replace all Tabs you input with 4 spaces. After configuring, these two settings should look like this:

Click for Bigger Image