Python For Loops

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A for loop allows you to iterate over a sequence of elements, such as a list, tuple, string, or range. It is useful for performing repetitive tasks on each item in a sequence.


Basic For Loop

The basic syntax of a for loop is as follows:

Explanation of Code:

The for loop iterates over each item in the sequence, executing the indented block of code for each item.

for item in sequence:
    # Code to be executed

Explanation of Code:

In this example, the loop prints each fruit in the fruits list.

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




Looping Through a String

You can use a for loop to iterate over each character in a string.

Explanation of Code:

The loop iterates over each character in the string and executes the code block for each character.

text = "Hello"
for char in text:
    print(char)




Looping Through a Range

The range() function generates a sequence of numbers, which can be used to control the number of times a loop executes.

Explanation of Code:

The range() function creates a sequence of numbers from 0 up to (but not including) the specified end value. In this example, the loop prints numbers from 0 to 4.

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




Looping with an Else Clause

You can include an else clause with a for loop. The else block will be executed after the loop finishes iterating over all items in the sequence.

Explanation of Code:

The else block runs after the loop completes normally.

for i in range(5):
    print(i)
else:
    print("Loop is finished")




Breaking out of a For Loop

You can use the break statement to exit a for loop prematurely, even if there are more items to iterate over.

Explanation of Code:

In this example, the loop prints numbers from 0 to 4 and then exits when i is equal to 5. The break statement immediately terminates the loop.

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




Skipping Iterations in a For Loop

The continue statement skips the current iteration and moves to the next iteration of the loop.

Explanation of Code:

In this example, the loop prints only odd numbers from 0 to 9. The continue statement allows you to skip specific iterations based on a condition.

for i in range(10):
    if i % 2 == 0:
        continue
    print(i)




Nested For Loops

You can nest for loops within each other to iterate over multi-dimensional data structures.

Explanation of Code:

This example prints each item in a 2D list (matrix) in a structured format. Nested for loops allow you to iterate over each item in a multi-dimensional sequence.

matrix = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

for row in matrix:
    for item in row:
        print(item, end=" ")
    print()




Python For Loops Example Code

Explanation of Code:

This program uses for loops to iterate over lists, strings, ranges, and demonstrates breaking out of loops, skipping iterations, and nesting loops.

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

# Looping through a string
text = "Hello"
for char in text:
    print(char)

# Looping through a range
for i in range(5):
    print(i)

# Looping with an else clause
for i in range(5):
    print(i)
else:
    print("Loop is finished")

# Breaking out of a for loop
for i in range(10):
    if i == 5:
        break
    print(i)

# Skipping iterations in a for loop
for i in range(10):
    if i % 2 == 0:
        continue
    print(i)

# Nested for loops
matrix = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

for row in matrix:
    for item in row:
        print(item, end=" ")
    print()




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