Tutorial on while loop

[@anishbhattacharya9582]

# find the no. of digits in a number :) a=str(abs(int(input("give any integer:")))) print(len(a)) easy way

[@avenumadhav3568]

factorial: 2:40 3:17 4:00 digits: 7:55 8:50 9:00 9:19 9:30 reverse: 12:20 13:45 15:08 15:22 15:43 16:00 16:30 17:17 20:12 21:07 21:42 palindrome: 25:45 26:28 26:50

[@kizhakkan]

In problem no.3 why cant we just multiply 'rev' by negative one (-1) to get the final result instead of subtracting two times 'rev' from 'rev'? Is there anything wrong in doing so? Is it not a normal convention? Am I missing here something?

[@storiesshubham4145]

Yes I also did same

[@saunakroychowdhury5990]

No, you are correct. In this, he made it more complex than necessary. Do it once, and if the input number was less than 0, rev *= -1 (end of if) print(rev)

[@meriid7017]

Umm, in palindrome case, we just have to print 'Palindrome' or 'Not Palindrome'. So, can't we just drop the negative case and just go by the absolute (+ve) value as we don't have to bother the negative sign for checking palindrome?

[@shreyapal6111]

In Problem 3 [Reverse the digits in the given number], why did we use _print(rev - 2 * rev)_ instead of _print(-rev)_ to print the negative of rev?

[@bhaskartrivedi3114]

could also be (0 - rev)

[@avenumadhav3568]

can we also not use while loop and do it? num = int(input()) s = str(abs(num)) if num>=0: print(int(s[::-1])) else: print(int('-'+(s[::-1])))

[@VENKATAKRISHNANG-h7c]

​@@avenumadhav3568thanks for this simple code.

[@1nsh]

In question number 2 we could have also done ---> num = int(input("Enter the number :")) /n (in next line) print(len(str(num))) This would have been way easier than the solution tought in this lecture

[@NeetSheth]

then -1 would give 2. you will have to add a if block to this.

[@ShubhamKumar-ty6ly]

Use abs(len(str(num)))

[@saumilbhatkar2694]

Easier way to do it: n=(str(input('Enter a Number:'))) n=n.lstrip('-') print(len(n))

[@SamparkLakshya]

what about num = int(input('Enter a number: ')) num_string = str(num) length = len(num_string) if num >= 0 : print(length) else : print(length - 1)

[@bharathraghu9195]

As someone new to coding, how to get acquainted with the logic of the code?

[@ABHARNAHRAJARAMMOHAN]

i would recommend datacamp. There are python tutorials especially for data science and beginners.

[@saunakroychowdhury5990]

logic is a natural thing. first you brainstorm and try at least something, if you fail, think harder, if you still fail, look for solution. Learn thoroughly, repeat. Eventually, it will come naturally

[@vjickstra]

20:10 Can't we just add a minus sign before printing rev. Like print(-rev). It seems to work fine.

[@TheUnknownU]

print(rev * -1) can we use this too?

[@05-ajitkulkarni88]

WE CAN ALSO SOLVE THE PROBLEM-3: num=int(input("enter the no.")) rev=str(num) print(rev[: :-1]

[@tauxic]

can you please explain the last line?

[@bhaviniee]

its a shortcut used in strings to reverse it@@tauxic

[@nitinfaldoliya656]

here - will also be shifted in last

[@sarthaksingh601]

4:49 the code now fails the test case (num = 0)

[@rohinibharti4463]

We can print fact for that case

[@umarulf]

i have doubt question 3

[@TKKARTIK-t4d]

We can use this as well for reversing of the digits of the number for both postive or negative just using if & elif n = int(input("Enter the number:", )) if(n>0): str_ = str(n) print(str_[::-1]) elif(n

[@learnwithrr1230]

reverse digit program fails when i entered 0123 and 1230 why? how to rectify it?

[@saunakroychowdhury5990]

No, it shouldn't fail. Perhaps you made some mistakes

[@arifinonim4677]

problem 3: n = int(input("Enter a number: ")) num = abs(n) rev = num % 10 num = num // 10 while(num > 0): r = num % 10 num = num // 10 rev = rev*10 + r if(n >= 0): print(rev) else: print(rev * (-1))

[@reddygopichand2002]

12:20 reverse the digits num = abs(int(input())) print(str(num)[::-1]) test case for negative fails!!

[@raj_patel]

num = int(input()) if(num == 0): print(0) elif(num > 0): print(str(num)[::-1]) else: num = abs(num) print((int(str(num)[::-1])) * (-1))

[@raj_patel]

ye wala sayad work karenga :)

[@steveraphaelpulikottil5755]

Problem 2 i/p 0 Exo/p should be 0, right??

[@SOUMAYGUPTA24]

problem-3 n = int(input("Enter a number: ")) num = str(abs(n)) num = num[::-1] if(n>0): print(num) else: print("-"+num)

[@reddygopichand2002]

Short answer: - 25:45 palindrome n=abs(int(input())) p=str(n) r=p[::-1] rint=int(r) if (n==rint): print("palindrome") else: print("not palindrome")

[@AryanGupta-eb2tp]

problem 3 code will not work on 10,20,30,800. Basically number ending with 0 will not work with this code

[@saunakroychowdhury5990]

Well! guess what? it's working. Kindly check before commenting.

[@piushdas6188]

@@saunakroychowdhury5990 I have also Checked , But it is not working for me as well

[@piushdas6188]

In case of 10 , it only prints 1 , technically it should be printing 01 right ???

[@CherryIITM]

My code literally, for q.2 a=abs(int(input())) a=str(a) print(len(a)) Can we use this? Is this Correct?

[@rituparnadas8344]

Only the following is enough: a = input() if a[0] == '-': print(len(a) - 1) else: print(len(a)) You don't have to convert the input into an integer and then into a string, because in Python the input is by default a string. P.S. Edited the code, I hadn't considered negative numbers before.

[@CherryIITM]

@@rituparnadas8344 Yes, You're right.

[@storiesshubham4145]

@@rituparnadas8344 No it's not working. We have to change it to string. Just now did it in replit

[@storiesshubham4145]

This will not work for negative numbers. -2 is giving length=2 which is clearly false. We can take the length of abs(n) and then add 1 to length if n

[@rituparnodhar6265]

@@rituparnadas8344 The logic is correct but we are talking about numbers so maybe the approach is not correct. Btw, similar names.🤝

[@reddygopichand2002]

Short answer: - 7:55 number of digits n=abs(int(input())) import math result=int(math.log(n,10))+1 print(result )

[@Dexter4o4]

More shorter :) n = abs(int(input ()) b = str(n) Print(len(b))

[@ranjeet_sohanpal]

Which compiler is being used by Sir ?

[@vishalmadhesia884]

spider

[@selvamselvam7960]

Problem 2: digit=digit+1 Digit=1+1=2 please someone explain this

[@jussstdoiit]

question no 4 easily is num = (int(input("enter your number: "))) int= abs(num) int = (str(int)) if int == int[::-1]: print("Palindrome") else: print("NOT a palindrome")

[@SOUMAYGUPTA24]

problem-3 n = int(input("Enter a number: ")) num = str(abs(n)) num = num[::-1] if(n>0): print(num) else: print("-"+num)

[@SOUMAYGUPTA24]

please let me know if this is a valid piece of code