data_types.md

Data Types in Python

data type	description	composite	mutable
int	integer numbers	no	no
float	floating-point numbers	no	no
string	characters	no	no
bool	True or False	no	no
list	sequence of items	yes	yes
tuple	immutable sequence	yes	no
dict	lookup table	yes	yes
set	collection of unique items	yes	yes
NoneType	just nothing	no	no

Basic and composite data types

Basic means that a data type does not contain any other types. Composite means that a data type contains other types.

Immutable and mutable data types

In Python there are basic and composite data types. The values of basic data types cannot be changed, they are immutable. Most of the composite data types are mutable.

The immutable data types in Python are:

• Boolean (True / False)
• Integer (0, 1, -3)
• Float (1.0, -0.3, 1.2345)
• Strings ('apple', "banana") - both single and double quotes are valid
• None (aka an empty variable)
• Tuples (multiple values in parentheses, e.g. ('Jack', 'Smith', 1990))

The mutable data types are

• List [1, 2, 2, 3]
• Dictionary {'name': 'John Smith', 'year': 1990}
• Set {1, 2, 3}