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Python 3 Program to Add Two Numbers Using Recursion in Terminal Tutorial For Complete Beginners
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Jun 1, 2025
Get the full source code of application here:
View Video Transcript
0:00
uh hello guys uh welcome to this video
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So in this video I will show you a very
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important competitive program which is
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asked inside interviews Whenever you go
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to interviews it will be asked what is
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the way by which we can add two numbers
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in Python using the concept of recursion
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Recursion is a concept in which we call
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the same function
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inside let me show you the concept where
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we call the function selflessly So we
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have a function inside Python here So
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let's suppose I define this recursive
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function and uh I pass a value here of a
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and here I will simply compare this
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value If a reaches to zero then we break
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out of this loop and we simply print
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out hello and we simply break until
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that we actually call the same function
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right here we simply decrement the value
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a minus one So essentially we declared
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this recursive function
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We take this input as an argument here
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the value of a Then we compare it inside
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this if condition that if the value of a
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reaches to zero then we print this
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statement of hello and we break out of
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this function and until that we
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recursively call this function the same
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function and decrement the value of a So
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now let me just call this function So if
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I
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say the value of a initial value of a is
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five So now the how the function will
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execute So you can just see whenever I'm
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calling this function the initial value
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of a is equal to five So it will reach
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right here It will be five
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here And now this condition will
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evaluate to false here This will not be
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executed Then it will it will come here
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So the a value will be decremented So 5
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- 1 So this will be four So this will
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now
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be
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four So this will again come right here
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4 -
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1 This will be three So this again will
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be 3 This will be 3 - 1 Now this will be
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2 Again this will come So 2 - 1 is equal
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to 1 And again it will come 1 -
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1 So this will reach this condition here
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It the a will become zero And now at
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that time we will get this hello
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statement So we can even print
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out the value of a So if I try to
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execute this program if you
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see so it is saying that you should
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have
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indentation sorry we should have this
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else statement right
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Good Let me just delete this and again
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run this
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Uh let me just correct this error I
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think there is some kind of
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error Let me ask JPT here It
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will okay
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Yes Break outside
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loop Sorry This needs to be inside
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corrected version
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So
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sorry So now we simply return from this
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function by writing the return keyword
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not break Break is not there inside
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Python If you want to exit out the
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function we simply write return right
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here So now what happens If you see if I
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try to print out the value of a as well
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Initial value of a will be five And as
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you can see the output comes initial
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value is five then it becomes four 3 2 1
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and then at last we print out the value
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of hello So this is actually the concept
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of recursion and using the similar
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concept we will be adding two
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numbers So this function will now change
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here So we will simply
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define this function which will take two
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values a comma
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b and here inside this we will check for
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the value of
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b If it
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reaches zero then we simply return the
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a and then in the else scenario
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we again call the same function
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recursive at and this is the logic of
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this we increment the value of a by one
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and decrement the value of b by one So
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here we are incrementing it a + 1 and
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decrementing the value of v b minus one
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So this is the way by which we
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recursively add two numbers inside
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python So if I try to call this function
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initial value of a is let's suppose five
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and b is
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three So now the result will be 5 + 3 8
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But let me show you how it executes So
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if I go to the terminal and just add So
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now the result comes out to be eight So
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how it executes this is the most
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important thing So now initial value as
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you can see the a value is 5 b is 3 So
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initial is a is equal to 5 b is equal to
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3 So now we come to our
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function So here b is not equal to zero
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So this will not execute We come to this
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We again call this function So we
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increment So now the value of a becomes
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5 + 1 is equal to 6 and b becomes 3 - 1
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2 So 6 2 We again call this function So
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b is not equal to 0 So again it will
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ignore this And again 6 +
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1 comes out to be 7 And again 2 - 1
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comes out to be 1 So 7A
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1 and then again it will call itself So
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b is not again zero So again it will
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come to this function again 7 +
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1 is equal to 8 and then 1 - b value is
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1 So 1 - 1 is equal to zero So now the
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argument becomes
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8 comma
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0 So now if we are checking here if B's
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value is equal to zero So in this case B
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is zero So now we are returning A which
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is 8 So we are simply returning from
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this function return is equal to and
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printing out 8 So in this way we are not
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directly adding 5 + 3 but instead we are
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in incrementing a every time and
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decrementing b This is the mathematical
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logic behind recursively adding two
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numbers So if you want to add two
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numbers essentially the logic is we
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increment every time this number and
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decrementing this one So 5 + 1 6 and 3 -
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1 2 So essentially we're transferring
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this to this
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So this is the logic how we can add
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recursively two numbers This is a
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program So I hope that I have explained
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you perfectly in this video Uh thank you
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very much for watching this video and
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also check out my website
8:37
freemediattools.com uh which contains uh
8:40
thousands of tools
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