Python Control Flow Statement– A Beginner’s Guide -

What is Control Flow?
Conditional Statements
Loops
Loop Control Statements
Worthwhile Books to learn Python from

What is Control Flow?

Control flow is the order in which instructions in a computer program are executed, moving beyond simple top-to-bottom sequence using statements like if/else (decisions) and for/while loops (repetition) to create dynamic behavior, allowing programs to make choices, repeat tasks, and call functions, making them powerful and efficient. It dictates program logic, enabling branching and looping based on conditions or data, which is fundamental for complex software.

Conditional Statements

Conditional statements allow a program to make decisions based on conditions. They help the program choose different paths of execution depending on whether a condition is true or false. In Python, conditions are evaluated using comparison and logical operators.

If Statement

Executes the block only when the if condition is True

age = 18
if age >= 18:
    print("Eligible to vote")

if-Else Statement

The else block runs when the if condition is false.

age = 16
if age >= 18:
    print("Eligible to vote")
else:
    print("Not eligible to vote")

If-Else-Elif Statement

Used when there are multiple conditions to check.

marks = 75

if marks >= 90:
    print("Grade A")
elif marks >= 60:
    print("Grade B")
else:
    print("Grade C")

Try to get the input from user like we did in the last post

Loops

Loops are used to execute a block of code repeatedly until a certain condition is met.

for Loop

Used to iterate over a sequence such as a list, string, or range.

for i in range(5):
    print(i)

while Loop

Runs as long as the given condition remains true.

count = 0
while count < 5:
    print(count)
    count += 1

Nested Loops

A loop inside another loop, commonly used for patterns or matrix-like data.

for i in range(3):
    for j in range(2):
        print(i, j)

Loop Control Statements

break

Stops the loop immediately.

for i in range(10):
    if i == 5:
        break
    print(i)

#prints 0-4 and breaks at 5

continue

Skips the current iteration and moves to the next one.

for i in range(5):
    if i == 2:
        continue
    print(i)

#skips 2 and prints the rest

pass

Acts as a placeholder where a statement is syntactically required.

if True:
    pass