Editing Intro to Programming and Data Science (Fall 2024)/Day 1 Tutorial (section)

===Division===

First, lets try some basic fractions:

<syntaxhighlight lang="python">
 1 / 2
</syntaxhighlight>

Sure enough, Python says that the answer is 0.5 which is the same as 1/2.

Let's try the same thing:

<syntaxhighlight lang="python">
 4 / 2
</syntaxhighlight>

Hey now! That last result is a little strange. When you divide a number in Python, even if the answer doesn't need a decimal place (like <code>4/2</code> which equals 2), you get an answer with a decimal point!

What's going on here is that in Python, division produces an what's called a <code>float</code> which essentially means a number with a decimal point.

When the Python interpreter goes to do the division, it knows that (unlike multiplication for example) division can lead to numbers that aren't whole numbers (like <code>1/2</code>) so it makes sure that the result will always include a decimal place just in case it's needed.


This shouldn't be important for this class but it might be worth knowing that older versions of Python (before version 3) would always round down and return integers instead of giving numbers with decimal places.