Editing Community Data Science Course/Day 1 Tutorial (section)

==Variables==

[[File:Fraction.png|100px]]

A lot of work gets done in Python using variables. Variables are a lot like the variables in math class, except that in Python variables can be of any data type, not just numbers.

 type(4)
 x = 4
 x
 type(x)
 2 * x

Giving a name to something, so that you can refer to it by that name, is called '''assignment'''. Above, we assigned the name 'x' to 4, and after that we can use <code>x</code> wherever we want to use the number 4.

Variables can't have spaces or other special characters, and they need to start with a letter. Here are some valid variable names:

<code>magic_number = 1500</code><br />
<code>amountOfFlour = .75</code><br />
<code>my_name = "Jessica"</code>

Projects develop naming conventions: maybe multi-word variable names use underscores (like <code>magic_number</code>), or "camel case" (like <code>amountOfFlour</code>). The most
important thing is to be consistent within a project, because it makes the code more readable.