Variables and numbers

Names for values

A variable is a name that points to a value. You make one with an equals sign. You do not need a special keyword.

city = "Lisbon"
temperature = 18
print(city)
print(temperature)

You can give a variable a new value at any time:

score = 10
score = 12

Python programmers write variable names in lower case, with underscores between words, such as final_score. A name cannot start with a digit or contain spaces.

Kinds of values

Every value has a type.

Type	Example	What it is
str	"Mars"	text
int	42	a whole number
float	3.5	a number with decimals
bool	True	True or False (with capital letters)

The function type(value) tells you the type.

Math

Operator	What it does	Example	Result
+ - *	add, subtract, multiply	7 * 2	14
/	divide (always gives a float)	7 / 2	3.5
//	divide and drop the decimals	7 // 2	3
%	remainder	7 % 2	1
**	power	7 ** 2	49

f-strings

An f-string puts values into text. Write the letter f before the opening quotation mark. Put a name or a calculation inside braces.

name = "Sam"
print(f"Hello, {name}!")
print(f"Two plus two is {2 + 2}.")

Your turn

Follow the five tasks. Each task is checked on its own.