Variables ¶

In programming languages, variables play a crucial role as they serve as labels for storing and manipulating data. A variable is essentially a symbolic name or identifier associated with a memory location that holds a value. These values can be numbers, characters, strings, or more complex data structures.

These are no different than variables in math. If I give you an equation $x + y$ and then tell you $x = 1$ and $y = 3$, you mentally put these numbers in the equation and get $1 + 3$. In fact, that is all valid Python!

In [1]:

x = 1
y = 3
print(x + y)

x = 1 y = 3 print(x + y)

4

This essentially is communicating to Python the same thing I was to you. You are saying: Hey Python, whenever you see x after this line, put 1 there. For y , put 3.

However, you have to tell Python about x and y before you use them. Like I said before, computers are dumb . If you tried to tell it about the equation x + y first, Python would panic because x and y don't exist yet. We will discuss this more later .