Python Tutorial: Math with dates

Want to learn more? Take the full course at https://learn.datacamp.com/courses/working-with-dates-and-times-in-python at your own pace. More than a video, you'll learn hands-on coding & quickly apply skills to your daily work. --- In the last lesson, we discussed how to create date objects and access their attributes. In this lesson, we're going to talk about how to do math with dates: counting days between events, moving forward or backward by a number of days, putting them in order, and so on. Let's take a step back. Think back to when you first learned arithmetic. You probably started with something like this: a number line. This one has the numbers 10 through 16 on it. A number line tells you what order the numbers go in, and how far apart numbers are from each other. Let's pick two numbers, 11 and 14, and represent them in Python as the variables a and b, respectively. We'll put them into a list, l. Python can tell us which number in this list is the least, using the min() function. min stands for the minimum. In this case, 11 is the lowest number in the list, so we get 11. We can also subtract numbers. When you subtract two numbers, in this case subtracting 11 from 14, the result is 3. Said another way, if we took three steps from 11, we would get 14. Now let's think about how this applies to dates. Let's call this line a calendar line, instead of a number line. Each dot on this calendar line corresponds to a particular day. Let's put two dates onto this calendar line: November 5th, 2017, and December 4th, 2017. Let's represent this in Python. We start by importing the date class from the datetime package. We create two date objects: d1 is November 5th, 2017, and d2 is December 4th, 2017. As before, we put them into a list, l. What Python is doing under the hood, so to speak, is not that different from putting the dates onto a calendar line. For example, if we call min of l, we again get the "least" date, which means the earliest one. In this ca