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Understanding Python Booleans

Booleans represent one of two values: True or False. In Python, Booleans are often used in conditions and comparisons. Booleans are essential in controlling the flow of the program using decision-making structures like if statements.

Basic Boolean Values

Booleans are derived from conditions and comparisons. When you run a comparison in Python, it will return a Boolean value, either True or False.

Example of Basic Boolean Values

# Basic Booleans
is_true = True
is_false = False
print(is_true)
print(is_false)

Output

True

False

Explanation: In this example, is_true holds the value True, and is_false holds the value False. These are basic Boolean values in Python.

Example: Boolean from Comparisons

# Boolean from comparisons
x = 5
y = 10
is_equal = x == y   # x equals y
is_less = x < y     # x is less than y
print(is_equal)
print(is_less)

Output

False

True

Explanation: Here, x == y checks if x equals y, returning False. The comparison x < y returns True because x is less than y.

Boolean Comparisons

Booleans are often the result of comparisons. Python supports several comparison operators, such as == (equal to), != (not equal to), > (greater than), and < (less than).

Example of Boolean Comparisons

# Boolean Comparisons
x = 10
y = 20
is_equal = x == y   # Checks if x is equal to y
is_greater = x > y  # Checks if x is greater than y
is_not_equal = x != y  # Checks if x is not equal to y
print(is_equal)
print(is_greater)
print(is_not_equal)

Output

False

False

True

Explanation: The comparison x == y checks whether x is equal to y. Since 10 is not equal to 20, the result is False. Similarly, x > y checks if x is greater than y, and the result is also False. However, x != y evaluates to True since x and y are not equal.

Boolean in Conditional Statements

Booleans are commonly used in conditional statements to control the flow of the program. An if statement evaluates a Boolean expression, and if the result is True, the block of code under it is executed.

Example with Conditional Statements

# Boolean in conditional statements
x = 15
if x > 10:
    print("x is greater than 10")
else:
    print("x is not greater than 10")

Output

x is greater than 10

Explanation: The if statement evaluates the Boolean expression x > 10. Since x is 15, which is greater than 10, the condition is True, and the first block of code is executed, printing "x is greater than 10".

Example with Multiple Conditions

# Boolean with multiple conditions
x = 5
y = 15
if x < 10 and y > 10:
    print("Both conditions are true.")
else:
    print("One or both conditions are false.")

Output

Both conditions are true.

Explanation: The if statement checks two conditions: x < 10 and y > 10. Since both conditions are true, the first block of code is executed, printing "Both conditions are true.".

Boolean and Logical Operators

Python supports logical operators like and, or, and not to combine or modify Boolean expressions.

Example with Logical Operators

# Boolean with logical operators
x = 5
y = 10
is_within_range = x > 0 and y < 20  # Checks if both conditions are true
is_outside_range = not is_within_range
print(is_within_range)
print(is_outside_range)

Output

True

False

Explanation: The expression x > 0 and y < 20 checks if both conditions are true. Since x = 5 and y = 10, both conditions are true, so is_within_range is True. The not operator reverses this value for is_outside_range, making it False.

Truthiness and Falsiness

In Python, non-Boolean values can also be evaluated in a Boolean context. For example, empty sequences (such as an empty list or string) are considered False, while non-empty sequences are considered True.

Example of Truthy and Falsy Values

# Truthy and Falsy values
empty_list = []
non_empty_list = [1, 2, 3]
empty_string = ""
non_empty_string = "Hello"
print(bool(empty_list))   # False
print(bool(non_empty_list))  # True
print(bool(empty_string))    # False
print(bool(non_empty_string))  # True

Output

False

True

False

True

Explanation: The bool() function evaluates the truth value of an object. Empty sequences such as an empty list [] or an empty string "" are evaluated as False, while non-empty sequences are evaluated as True.

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