Decision Making in Python
Hey there! In this guide, we'll explore decision-making in Python. Decision-making constructs allow you to execute code based on certain conditions. Let's dive in!
Decision Making
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Python supports several decision-making constructs that allow you to execute code based on conditions.
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We will go over the different decision-making options available in Python.
Video Explanation
1. If Statements
The simplest decision-making structure in Python is the if statement, which executes a block of code if a certain condition is met.
num = 8 # Initialize variable 'num' with a value of 8
if num > 0: # Check if the value of 'num' is greater than 0
print('The number is positive.') # Print a message if the condition is true
2. If-Else Statements
The if-else statement allows you to execute one block of code if the condition is true, and another if the condition is false.
num = 11 # Initialize variable 'num' with a value of 11
if num % 2 == 0: # Check if 'num' is even
print('The number is even.') # Print this message if 'num' is even
else: # Otherwise, execute this block
print('The number is odd.') # Print this message if 'num' is odd
3. Else If (Elif) Statements
The elif statement (short for else if) allows you to check multiple conditions in sequence and execute the first block of code where the condition is true.
num = 15 # Initialize variable 'num' with a value of 15
if num > 20: # Check if 'num' is greater than 20
print('The number is greater than 20.') # Print this message if 'num' is greater than 20
elif num == 15: # Check if 'num' is equal to 15
print('The number is 15.') # Print this message if 'num' is equal to 15
else: # Otherwise, execute this block
print('The number is less than 20.') # Print this message if 'num' is less than 20
4. Nested If Statements
You can use if statements inside other if statements, known as nested if statements, to evaluate more complex conditions.
num = 7 # Initialize variable 'num' with a value of 7
if num > 0: # Check if 'num' is positive
if num < 10: # Check if 'num' is less than 10
print('The number is positive and less than 10.') # Print this message if both conditions are true
5. Ternary Operator
Python also supports a shorthand for the if-else statement, called the ternary operator.
age = 18 # Initialize variable 'age' with a value of 18
can_vote = 'Yes' if age >= 18 else 'No' # Use the ternary operator to check if 'age' is 18 or older
print(can_vote) # Output: 'Yes'
6. Switch Statements (Python 3.10+)
From Python 3.10, the match-case statement is introduced, which works similarly to a switch statement in other languages.
day = 2 # Initialize variable 'day' with a value of 2
match day: # Use match-case to determine the day of the week
case 1:
print('Monday') # Execute if 'day' is 1
case 2:
print('Tuesday') # Execute if 'day' is 2
case 3:
print('Wednesday') # Execute if 'day' is 3
case _: # Default case
print('Invalid day') # Execute if none of the above cases match
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