Python Boolean (original) (raw)

Boolean is a built-in data type that represents only two values: True and False. It is commonly used to check conditions and represent the truth value of expressions in a program.

Python `

a = True print(type(a))

b = False print(type(b))

Output

Evaluate Variables and Expressions

We can check or convert values into Boolean form using the bool() function. It returns either True or False based on the value of the expression.

**1. bool() Function: converts any value or expression into its corresponding Boolean value.

Python `

x = None print(bool(x))

x = () print(bool(x))

x = {} print(bool(x))

x = 0.0 print(bool(x))

x = 'GeeksforGeeks' print(bool(x))

Output

False False False False True

**Explanation: Empty values like None, (), {} and 0 are treated as False and non-empty strings or values are treated as True.

**Note: Python automatically evaluates values as True or False in conditions like if statements, so using bool() explicitly is not always required.

**2. Integers and Floats: numbers can also behave like Boolean values. Zero is considered False, while any non-zero number is considered True.

Python `

a = 0 print(bool(a))

b = 1 print(bool(b))

c = -9.7 print(bool(c))

Boolean Operators

Boolean operators are used to perform logical operations on True and False values. These operators help in decision-making in programs.

**1. OR Operator: returns True if at least one condition is True.

Python `

a = 5 b = 3 c = 8

if a > b or b < c: print("True")

**Explanation:

a > b is True (5 > 3)
b < c is True (3 < 8)
Since at least one condition is True, the result is True.

**2. AND Operator: returns True only if all conditions are True, otherwise it returns False.

Python `

a = 0 b = 2 c = 4

if a > b and b < c: print(True) else: print(False)

if a and b and c: print("True") else: print("False")

**Explanation:

First condition fails because a > b is False.
0 is treated as False, so a and b and c also becomes False.

**3. NOT Operator: reverses the Boolean value of an expression.

Python `

a = 0 if not a: print("False")

**Explanation: 0 is considered False, not False becomes True, so the condition executes.

**4. Equality Operators (== and !=): == operator returns True if both values are equal, while the != operator returns True if the values are not equal.

Python `

a = 0 b = 1

if a == 0: print(True)

if a == b: print(True)

if a != b: print(True)

**Explanation:

a == 0 is True.
a == b is False, so nothing prints.
a != b is True.

**5. Identity Operator (is): checks whether two variables refer to the same object in memory.

Python `

x = 10 y = 10

if x is y: print(True)

**Explanation: Both variables refer to the same memory object, so x is y is True.

**6. Membership Operator (in): checks whether a value exists inside a sequence like a list, tuple, or string.

Python `

a = [1, 2, 2]

if 1 in a: print(True)

**Explanation: 1 is present in the list, so the condition becomes True.