Numbers, text, and Boolean values

Python values have types. Whole numbers are int values; numbers with a decimal point are float values; text in quotes is a str value; and True or False is a bool value. A Boolean represents a true-or-false state. The value determines its type; a variable name can later be assigned a value of another type.

sessions = 3             # int: whole number
hours = 1.5             # float: decimal number
name = "Sam"            # str: text
finished = False        # bool: True or False
print(type(sessions))
print(type(name))

<class 'int'>
<class 'str'>

Text and numbers differ

The number 3 and the text "3" look similar when printed, but have different types. You can calculate with the number. Text can be joined to other text. Adding a number directly to text raises a TypeError.

print(3 + 2)
print("3" + "2")

5
32

Represent no value

None is a special value meaning that no value is present. It is different from 0, an empty string, and False. Later, a function can return None to indicate that it did not produce a usable number.

result = None
print(result)
print(type(result))

None
<class 'NoneType'>

Why this works

A value has a type, while a variable name can later refer to a different value. That distinction explains why 3 + 2 calculates 5 but "3" + "2" joins text into "32". None is the built-in value for an absent result; it is not a number. type() helps inspect a value when an input or calculation behaves unexpectedly.

Practice

Create one int, float, str, and bool value, plus a name set to None. Print each value and its type. Remember that True, False, and None begin with capital letters and are not surrounded by quotes.

Try another case

What are the types of 4, 4.0, "4", and False?