Data Types

Every value in Python has a type, which determines what you can do with it. The core built-in types are int (whole numbers), float (decimal numbers), str (text), bool (True/False), and None (the absence of a value).

type(25)        # <class 'int'>
type(25.0)      # <class 'float'>
type("25")      # <class 'str'>
type(True)      # <class 'bool'>

"25" (a string) and 25 (an integer) look similar but behave completely differently — "25" + "5" joins the text into "255", while 25 + 5 adds the numbers into 30.

Common mistakes

• Assuming text that looks numeric behaves like a number. Convert explicitly with int("25") or float("25.0") first.