Python variables and data types

A variable simply stores data inside a named piece of memory:

Declaring variables

Recall in the input article that we stored input for later use inside a thing called a variable:

name = input('Please enter your name')

We then noticed how we don't need to use a keyword like "let" (in JavaScript, for example) to declare variables! Simply state the variable name and the data:

variable = value

The value could have any type: string (text), number, Boolean (a true or false value) or even another variable!

Casting values to specific types

However, to ensure that a value has a certain data type, we can cast it by specifying its type in front of it:

position1 = str(1)
position2 = str(10)
position3 = str(11)

So, we have just ensured that each of those variables have string representations of those numbers, on which we can no longer perform mathematical operations! Were we to do this:

positionX = position1 + position2 + position3

We would have positionX with a value of "11011" (a string concatenation or "gluing together" of "1" and "10" and "11") instead of "22" (adding the numbers 1+10+11)!

Finding the type of a variable

To find out the type of a variable, Python has a built-in function simply called type:

temperature = 100 
print(type(temperature))
# <class 'int'>

Other data types

More basic "formats" of data in Python (with their Python name) include:

• integer ("int")
  • discrete or whole numbers like -2, 0, 3, 700
• float
  • decimal numbers like -2.5, 0.29, 1.18
• boolean ("bool")
  • true or false
• string ("str")
  • text that can include "numbers" (or rather, digits)