Loops

Loops are control flow statements that allow you to repeatedly execute a block of code. Python offers two primary loop types: for and while.

For Loop

A for loop iterates over a sequence (like a list, tuple, string, or range) and executes a block of code for each item in the sequence.

Python

fruits = ["apple", "banana", "cherry"]

for fruit in fruits:

  print(fruit)

Iterating over a range:

Python

for i in range(5):

  print(i)

While Loop

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

Python

count = 0

while count < 5:

  print(count)

  count += 1

Loop Control Statements

• break: Terminates the loop entirely.

• continue: Skips the current iteration and moves to the next.

• else: Optional clause executed when the loop completes normally (without break).

Python

for num in range(10):

  if num == 5:

    break

  print(num)

for num in range(10):

  if num % 2 == 0:

    continue

  print(num)

Nested Loops

You can have loops within loops:

Python

for i in range(3):

  for j in range(2):

    print(i, j)

Important Considerations

• Indentation is crucial for defining the loop body.

• Be careful with infinite loops (while loops without a clear exit condition).

• Use break and continue judiciously to control loop flow.

By understanding these loop constructs, you can effectively automate repetitive tasks and process data efficiently in your Python programs.