Decision Making || Python Programming tutorial 4

Welcome

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So today here you are going to learn decision making in python ( if, elif, if-else, nested if statements in python). Decision-making statements in programming languages decides the direction of the flow of program execution. Decision-making statements available in python are if, elif, if-else, nested if.

Decision making in python

if Statement

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if statement is the most simple decision-making statement. It is used to decide whether a certain statement or block of statements will be executed or not i.e if a certain condition is true then a block of statement is executed otherwise not.

Syntax:

    if  condition:

            #Statements to execute 

Here, conditions after evaluation will be either true or false. if statement accepts boolean values – if the value is true then it will execute the block of statements below it otherwise not. We can use condition with bracket ‘( )’ also.

Flowchart: 

Below we have given a small illustration of if statement.

if-else Statement

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The if statement alone tells us that if a condition is true it will execute a block of statements and if the condition is false it won’t. But what if we want to do something else if the condition is false. Here comes the else statement. We can use the else statement with if statement to execute a block of code when the condition is false.

Syntax:

    if  (condition):

            #Statements to execute 
     else:
            #Statements in this block executes
            # if the condition is false

Below we have given a small illustration of if else statement.

Nested Statement

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A nested if is an if statement that is the target of another if statement. Nested if statements mean an if statement inside another if statement. Yes, Python allows us to nest if statements within if statements. i.e, we can place an if statement inside another if statement.

Syntax:

    if  (condition 1):

            #Statements to execute when condition 1 is true
            if  (condition 2):

                     #Statements to execute when condition 2 is true
            # Inner if block ends here
     # Outer if block ends here

Below we have given a small illustration of nested if statement.

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