Boolean: a True or False value.

Creating booleans

Like other values, boolean values can be created manually and assigned to variables:

raining = True

Comparison operators produce booleans:

x = (10 > 12)      # x is now False, because 10 IS NOT larger than 12
y = (42 * 2 < 100) # y is now True, because 42*2 IS smaller than 2

Logical operators also produce booleans:

a = True
b = False

c = a and b  # c is now False
d = a or b   # d is now True

e = not a    # e is now False
f = not b    # f is now True

Use of booleans

Booleans are used in conditional statements, loops, comparison operators and logical operators.

Boolean in conditional statement

if (x > 10):
  print("Number is larger than 10")
  print("Number is smaller or equal to 10")

The code above will print "Number is larger than 10" if the value of x is an integer larger than 10. Otherwise, it will print "Number is smaller or equal to 10".

Boolean in loop, with comparison

a = 0
while (a != 7):
  a = a + 1

The code above will print "Hi!" seven times. != is a comparison operator.

bool() function

The bool() function takes one argument and returns a boolean. The logic behind conversion is explained in truth value testing.

bool("Good evening!")  # => True
bool("")               # => False

bool(42)               # => True
bool(0)                # => False