Python - Control Statements

Control Statements:

1. Conditional Statements

Conditional Statement	Description
if	An if statement is used to test an expression for truthiness and execute some code if the expression is true
elif	An elif (else if) statement is used to chain multiple conditions in an if statement. It executes its block of code if its condition is true and all previous conditions have been false
else	An else statement catches anything which isn’t caught by the preceding conditions
if...else	An if...else statement provides an alternate block of code that is executed if the if condition is false
if...elif...else	An if...elif...else statement allows you to chain multiple conditions and provide an alternate block of code that is executed if all conditions are false

1. Looping Statements

Looping Statement	Description
for	A for loop is used for iterating over a sequence (that is either a list, a tuple, a dictionary, a set, or a string)
while	A while loop can execute a set of statements as long as a condition is true
nested loops	A nested loop is a loop inside a loop. The for loop and the while loop can be nested
break	The break statement can stop the loop before it has looped through all the items
continue	The continue statement can stop the current iteration of the loop, and continue with the next
pass	The pass statement is used as a placeholder for future code. When the pass statement is executed, nothing happens, but you avoid getting an error when empty code is not allowed

Examples:

1. If elif else Statement:

    age = 18
   
    if age < 13:
        print("You are a child.")
    elif 13 <= age < 18:
        print("You are a teenager.")
    else:
        print("You are an adult.")
   

2. For Loop :

    # List of numbers
    numbers = [1, 2, 3, 4, 5]
   
    # variable to store the sum
    sum = 0
   
    # iterate over the list
    for num in numbers:
        sum = sum + num
   
    # print the sum
    print("The sum is", sum)
   

3. While Loop:

    # initial value of counter
    counter = 0
   
    # while loop
    while counter < 5:
        print("Counter is", counter)
        counter = counter + 1
   

4. Nested Loops:

    # Outer loop
    for i in range(3):
        print("Outer loop iteration:", i)
           
        # Inner loop
        for j in range(3):
            print("   Inner loop iteration:", j)