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COMPUTER SOFTWARE APPLICATION - CITS

Looping

The following loops are available in Python to fulfil the looping needs. Python offers 3 choices for running the
loops. The basic functionality of all the techniques is the same, although the syntax and the amount of time
required for checking the condition differ.
We can run a single statement or set of statements repeatedly using a loop command.
The following sorts of loops are available in the Python programming language.

S. No. Name of the loop Loop Type & Description
Repeats a statement or group of statements while a given condition is TRUE.
1 While loop
It tests the condition before executing the loop body.
This type of loop executes a code block multiple times and abbreviates the
2 For loop
code that manages the loop variable.
3 Nested loops We can iterate a loop inside another loop.

Loop Control Statements
Statements used to control loops and change the course of iteration are called control statements. All the objects
produced within the local scope of the loop are deleted when execution is completed.

Python provides the following control statements. We will discuss them later in detail.
Let us quickly go over the definitions of these loop control statements.

Name of the control
S. No. Loop Type & Description
statement
This command terminates the loop's execution and transfers the program's
1 Break statement
control to the statement next to the loop.
This command skips the current iteration of the loop. The statements following
2 Continue statement the continue statement are not executed once the Python interpreter reaches
the continue statement.
The pass statement is used when a statement is syntactically necessary, but
3 Pass statement
no code is to be executed.

The for Loop
Python’s for loop is designed to repeatedly execute a code block while iterating through a list, tuple, dictionary, or
other iterable objects of Python. The process of traversing a sequence is known as iteration.

Syntax of the for Loop
1 For value in sequence:
2 { code block }
In this case, the variable value is used to hold the value of every item present in the sequence before the iteration
begins until this particular iteration is completed.
Loop iterates until the final item of the sequence are reached.
Code
1 # Python program to show how the for loop works

2
3 # Creating a sequence which is a tuple of numbers
4 numbers = [4, 2, 6, 7, 3, 5, 8, 10, 6, 1, 9, 2]
5
6 # variable to store the square of the number

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CITS : IT&ITES - Computer Software Application - Lesson 120 - 137 CITS : IT&ITES - Computer Software Application - Lesson 120 - 137