Control Flow

Control flow refers to the order in which a program’s statements are executed, allowing you to make decisions, repeat actions, or skip code based on conditions. Python provides several control flow structures, such as:

Conditional Statements
Loops
Control Statements
Exception Handling

1. Conditional Statements

Conditional statements allow you to execute code based on specific conditions. The primary constructs are if, elif, and else.


age = 20
if age >= 18:
    print("Adult")
elif age >= 13:
    print("Teenager")
else:
    print("Child")
# Output: Adult

2. Loops

a) While Loop

A while loop repeatedly executes a block of code as long as a specified condition is True.

count = 0
while count < 5:
    print(count)
    count += 1
# Output: 0 1 2 3 4

Using break:

Exits the loop immediately

count = 0
num = 10
while num > 0:
    if num == 5:
        break
    print(num)
    num -= 1
# Output: 10 9 8 7 6

Using continue:

Skips the rest of the current iteration and checks the condition again.

num = 10
while num > 0:
    num -= 1
    if num % 2 == 0:
        continue
    print(num)
# Output: 9 7 5 3 1 (skips even numbers)

b) For Loop

A for loop iterates over a sequence (like a list, tuple, string, or range) to execute a block of code for each item.

fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
    print(fruit)
# Output: apple banana cherry

3. Loop Control Statements

break: Exits the loop

for i in range(10):
    if i == 5:
        break
    print(i)  # Output: 0 1 2 3 4

continue: Skips current iteration

for i in range(5):
    if i == 2:
        continue
    print(i)  # Output: 0 1 3 4

pass: Does nothing (placeholder)

for i in range(5):
    if i == 2:
        pass
    print(i)  # Output: 0 1 2 3 4

4. Exception Handling (try/except)

Manages errors and exceptional cases.

try:
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero")
finally:
    print("Execution completed")
# Output:
# Cannot divide by zero
# Execution completed