Python Loops Explained | For Loop and While Loop | AIML EP-4 | CHiPSET Tech Articles

Loops in Python

Loops are used to execute a block of code repeatedly until a condition is met or all items in a sequence are processed. They help reduce repetitive code and make programs more efficient.

The main types of loops in Python are:

•For Loop

•While Loop

For Loop

A for loop is used to iterate over a sequence such as a list, tuple, string, or range. It executes a block of code once for each item in the sequence.

Syntax

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Understanding range()

Before learning loops, it is important to understand the range() function because it is commonly used with loops.

The range() function generates a sequence of numbers.

Example

print(range(5))

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Python starts counting from 0, so the ending value is not included.

Different Ways to Use range():

Using Only Stop Value:

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However in real life you may not notice this instead your interpreter will show this

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but for understanding purpose i will be showing how the sequence would be

Using Start and Stop Values

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Using Start, Stop and Step Values

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A for loop is used to iterate over a sequence such as a list, tuple, string, or range. It executes a block of code once for each item in the sequence.

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Explanation

•n = 4 stores the ending value for the loop.

•range(0, n) generates numbers from 0 to 3.

•for i in range(0, n) iterates through each number.

•print(i) prints the value of i.

Below is the flowchart of For loop:

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Iterating by Index of Sequences

A for loop can also access elements using their index values with the help of range() and len().

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here a is list right now just know how it works ,you will later come to know about lists ,as of now know that lists are sequence of elements in python

Explanation

•len(a) returns the total number of elements in the list.

•range(len(a)) generates index values from 0 to 2.

•a[idx] accesses list elements using their index.

While Loop

A while loop repeatedly executes a block of code as long as the given condition remains true. When the condition becomes false, the loop stops.

Syntax:

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Example:

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Explanation

•cnt = 0 initializes the counter variable.

•while (cnt < 3) checks the condition.

•cnt = cnt + 1 increases the counter value.

•The loop runs until the condition becomes false.

Infinite While Loop

An infinite while loop runs continuously because its condition always remains true.

Example

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Explanation

•while(True) creates a condition that is always true.

•"Hello Geek" keeps printing forever.

Note: Infinite loops should generally be avoided because they never stop automatically.

if you want to try you can at your own risk ,because once it starts it never concludes unless you manually interrupt or your system prunes the process