3.2 Booleans

Boolean in Python

A boolean in Python is a data type that can hold one of two possible values: True or False. It is often used in conditional statements to control the flow of a program. Booleans are derived from the concept of Boolean logic, which is fundamental in computer science.

Example

# Defining boolean variables
is_active = True
is_complete = False

# Using booleans in conditional statements
if is_active:
    print("The process is active.")
else:
    print("The process is not active.")



```python
# Boolean Comparisons
print("print(7 <= 10):", 7 <= 10)   # True
print("print(7 != 10):", 7 != 10)   # True
print("print(7 == 10):", 7 == 10)    # False

# Variables
num1 = 15
num2 = 30

print("\nnum1 is 15, num2 is 30")

if num1 < num2:
    print("num1 is less than num2")
else:
    print("num1 is not less than num2")

# Evaluating Truthiness
# Any non-empty string is considered True
# Any non-zero integer is considered True
# Empty lists and dictionaries are considered False
print("\nNon-empty string 'Python':", bool("Python"))  # True
print("Zero:", bool(0))                                # False
print("Non-empty dictionary {}:", bool({"key": "value"}))  # True
print("Empty dictionary {}:", bool({}))                # False

print(7 <= 10): True
print(7 != 10): True
print(7 == 10): False

num1 is 15, num2 is 30
num1 is less than num2

Non-empty string 'Python': True
Zero: False
Non-empty dictionary {}: True
Empty dictionary {}: False

Javascript Version

%%js
// Boolean Comparisons
console.log("console.log(7 <= 10):", 7 <= 10);  // true
console.log("console.log(7 != 10):", 7 != 10);  // true
console.log("console.log(7 == 10):", 7 == 10);  // false

// Variables
let num1 = 15;
let num2 = 30;

console.log("\nnum1 is 15, num2 is 30");

if (num1 < num2) {
    console.log("num1 is less than num2");
} else {
    console.log("num1 is not less than num2");
}

// Evaluating Truthiness
// Any non-empty string is considered true
// Any non-zero integer is considered true
// Empty arrays and objects are considered false
console.log("\nNon-empty string 'JavaScript':", Boolean("JavaScript"));  // true
console.log("Zero:", Boolean(0));                                      // false
console.log("Non-empty object {}:", Boolean({ key: "value" }));       // true
console.log("Empty object {}:", Boolean({}));                           // false

<IPython.core.display.Javascript object>