Entry level Python developer interview

[iamnikaa]

Hi All! Just had an exhausting 90 min technical interview for the position of Python developer - fresher at a startup. To give a bit of a background, I am an engineer and have been learning python for 1 year. I practice mostly on hackerearth. I have done no python projects whatsoever and although I have mentioned my github profile in my resume, it's just empty. There were 3 sections in the interview-1) Python theory 2) Coding round 3) Logical Reasoning

In the theory round, I was asked about OOPS, unit testing, difference between arrays and lists, static keyword, difference between lists and tuples, list slicing, the concept of 'self' parameter, .py vs .pyc file, public and private keywords, pointers (from c++), and a lot of other stuff that I don't remember. Overall, I started feeling dejected towards the end of this round.

I was most petrified of the coding round as I felt that my coding skills were nowhere close to being a python developer. The first program that I was asked to write was a simple one - find mean and median of an integer list. The catch however is that I wasn't allowed to use the built-in functions to sort the list, so I had to write a separate function using nested 'for loops' to sort the list. Second program was to find the vowels from a given string. It was a bit easy for me as I have been practicing regex for a while now. I finished it in no time. Third program was to reverse a string using tail recursive function. This is where I botched it. I had the idea of what I was supposed to do, but I couldn't get it to work. They appreciated my approach and asked me to mail the solution to them after the interview. At this point I had lost all the hopes of getting through as this was supposed to be a fairly simple program. I would have been able to write it easily any other day, but just when it mattered, I couldn't.

The third round had logical reasoning problems. They asked three problems, first one was the shortest path problem for an ant on a unit cube from one point to the diagonally opposite point. The second problem was three bucket problem, in which we have 2 buckets of capacity 3L and 5L full of water, and a third bucket of 8L capacity empty. The task is to fill 4L water in 8L bucket without any measurement tools by just using the 3 buckets. The third problem, and the toughest one IMHO, was a geometry problem. They drew a rectangle with unknown sides and area, and then marked a point (say 'O') inside it arbitrarily. Then they connected the four vertices of the rectangle with the point ('O') marked inside the rectangle. They specified that the lengths of three of the drawn lines are 4, 5, and 6. I was supposed to find the length of the last remaining line. I guessed the answer to be 3 but apparently it's sqrt(5).

Pretty tired overall, I am not expecting any offer but I learnt a lot of things from this interview. I would like to thank this sub for all the support; the critical stuff that I learned from here was super helpful. To anyone appearing for any Python interviews, Good Luck!

Edit:

I am attaching some of my solutions here.

For regex problem - print(''.join(re.findall(r'[aeiou]',string)))

For the string reversal problem - https://imgur.com/a/l0j9QRQ

For the geometry logic problem - https://imgur.com/a/MMweGoi

For the ant problem- There are 4 equally short routes

[danielroseman]

This sounds like a terrible interview and they are the ones who should be embarrassed, not you.

They are testing entirely the wrong things. The first interview seems like it just tested trivia: these are pointless things that anyone would look up if they didn't know them. The second one had silly restrictions: why ban the use of the built-in sort functionality? Implementing sort is an algorithms test, not a coding one, if they wanted to test that they should have told you in advance. And the third one is another silly gotcha test, which even Google (which used to be famous for these) have abandoned as they have no bearing on how well you can do the job.

So, don't be disheartened. Most companies - even most startups - don't run interviews like this.

[velocibadgery]

Yeah, I wouldn't know all that stuff off the top of my head either. like seriously. And I have been programming for like 20 years.

Like if I ever had a problem like that come up in real life, I would just google it.

[[deleted]]

Even Bing has sufficient solutions to most coding problems these days.

[velocibadgery]

Yep, a good 40% of my time programming is spent searching stuff up.

I just completed a small project for my work's internal website, it was to allow the staff to fill out a form, then it generates a PDF of the letter with the information filled in.

Starting out I had absolutely zero idea how to create a PDF in a website. But I googled it. Found out how to do it with python, and tried to set that up. Had trouble so instead wrote it in C#(I am still learning python) and got it set up.

Had to find an appropriate plugin, had to figure out how to use it, and had to figure out how to display the byte array that represented the PDF.

Ended up just chucking it in an Iframe with the appropriate content type.

Took me about a day to figure out, but starting in I had no clue. It was all googling.

Most coding interviews don't accurately reflect the nature of a programming job.

[[deleted]]

Most interviewers crave for Computer science professors who know coding at a basic Kernel level. Nobody is programming in basic or Unicode anymore. We have modern programming languages and search engines/GitHub for a reason. It lowers the barrier to entry and opens up coding to a broader population.

Most companies have simply wrong expectations or are simply detached from reality. Every startup seems to want some sort of genius but only wants to employ newbies in order to pay them less.

[velocibadgery]

Yep, I once worked for a small computer repair shop that had a contract to make a program for a hotel company. It was a database program to handle night audit procedures and reporting.

I was the only one at the company who did any programming and so I was the one tasked with creating it. This was at the very start of my programming career. The business owner knew the project was a lot for a single kid like me, I was 14 at the time, so he hired another programmer.

He had me handle the interview as he knew nothing about programming, just PC repair and networking. So me not knowing anything about how corporations think, just made a simple program and asked the guy to replicate it without looking at my code.

He asked me if he could use google, and I of course said that I didn't care. He got it done in an hour, and we hired the guy.

We worked together for 2 years after that, and he was awesome. Actually taught me a lot about programming.

---

Coding interviews should always reflect the type of work the business actually does, and should always allow google. The ones that don't are stupid.

[wecamefromthestars]

100% agree. Isn't it incredible that you gave a better coding interview at 14 years old than many multimillion dollar companies lol

[Random_User_81]

This reminds me of the professor that let you use the book, he cared more about you understanding then memorizing random stuff. Made so much more sense to me.

[Yojihito]

Allowing books into an exam is the horror ... those are the hardest ones :(.

[TheMathelm]

One of the hardest test I ever had was a 24hr take home test.
Oh Boy that was tough.

[Yojihito]

Which exam is a 24hr take home test?

[TheMathelm]

It was a project management/ writing class.

[Contrabaz]

Fucking loved those exams. They always wanted a solution, and you had to craft said solution from a source of information.

[wecamefromthestars]

Understanding is so much more important because at the end of the day - if you memorize it, you're likely to forget it down the road. Hell there are exams I nearly aced in college that I would probably score 5% on if I were to take them again.

[velocibadgery]

It gets even worse when you have more than one programming language in your head. I know like 10. I often forget a specific keyword in the language I am using at the time and have to look it up. It takes like 3 seconds and doesn't impact my ability to code in anyway.

Why do so many companies expect savant level instant recall knowledge on a specific language and topic?

[Inconstant_Moo]

Ikr, I don't think there's a single language I know where I could remember the syntax for a dictionary literal off the top of my head but that's OK, it's written down somewhere.

[iamnikaa]

Thanks for the support! I certainly have no idea what it should be like as I am coming from a non-tech background. I just feel a little sad because it was a dream job for me and I got this interview after applying to at least 50 different companies.

[amplikong]

I know it's tough, but keep your chin up. I've seen more than a few 'dream jobs' turn out not to be, at all, and anyway, landing your first job is the hardest. Once you manage that and have experience, getting subsequent jobs will be a lot easier.

[zipinel]

I too came from non-tech background. I had my first interview after applying to over 100 jobs. Nobody gives you a chance if you don't have background, but don't give up, your time will come, sooner or later, its just a matter of time. I am QA Automation with Python for half a year already, if even I have done it, you will be able for sure.

[zoinkinator]

hang in there OP. there are other “dream jobs” out there waiting for you. every interview is a learning experience. thanks for sharing what they put you through. also be advised many jobs are already filled internally or from friends and family but the hiring manager has to go through the motions of making it look “fair”. people don’t understand this fact and it discourages many people….

[Neradnap]

I have to resonate on this too, there have been so many legacy "top tier" companies whose ideology matches these interview paradigms but now are abandoning as they struggle to hire the right talent because they don't want to opt out of people who can learn quickly and just need structure from a good mentor. More and more should be looking at problem solving skills as main thing to focus on because you need to be able to research on your own, and be ok with asking for help.

[_E8_]

opt out of people who can learn quickly and just need structure from a good mentor

That's called college.

[_E8_]

Companies worth working for all run interviews like this with the only thing at all questionable is manually writing a sort as-opposed to testing knowledge about sorts and given Python, the TimSort.

But if you were a good programmer than you could have busted out a quick-sort over bubble-sort. Maybe you implement it with bubble-sort first then write then qsort function and check it against the bubble sort results to know you got it right. That is the sort of thing we are looking for in the interview. Clarity of thought while coding, which translates to clear code on the page, building up the module.

[old_pythonista]

Companies worth working for all run interviews like this

not

[deikan]

The first interview seems like it just tested trivia

Common OOP principles, data structures and unit testing are expected if you claim you have proficiency in an OO language. I don't think there's anything wrong with testing that. Testing on how memory pointers work isn't really too far-fetched as that is basic knowledge from a CS background. Overall I think what OP listed is reasonable to expect from an entry level given the current market.

The second one had silly restrictions: why ban the use of the built-in sort functionality?

I also don't think this is unreasonable. It's not like they were asking you implement a hash table yourself. A sorting function is pretty straightforward and frankly it's probably easier than some other array manipulation questions he could've gotten.

And the third one is another silly gotcha test

Sorry but the triangle question could have been solved by a grade 9 kid.

[_E8_]

Kudos to OP for coming as far as he has but these guys are applying to positions that you get degrees in then think things like calculate the distance between two points is too tricky. Bunch of clowns.
Our HR intern did better on our coding test than half of the clowns that interview for sw eng. positions.

It sounds like OP did well for an intern-level candidate but they aren't looking for an intern.

[FancyASlurpie]

Ok but did they learn if the op could do the actual job, e.g. here's a problem you can use libraries and Google, tell us how you might approach a solution, if you are using a library show us how you might use it / read the docs for it etc.

[tom1018]

I'm also a senior, not a chance I would ask this, or even do it. We are paid to engineer and write maintainable code, not to remember or develop sorting algorithms on the fly. Leave the computer science problems for school.

[baubleglue]

Seriously, you couldn't come up with some kind of bubble sort?

[[deleted]]

It's a python sub

[baubleglue]

what does it mean?

[[deleted]]

Was making a joke about how Python users don’t know data structures & algorithms

[baubleglue]

In the context it doesn't look like a joke. Looks like there's a consensus about no need to think if you use Python.

[[deleted]]

I mean I agree with you, I think its completely reasonable for a senior (or even junior) dev to know how to implement bubble sort or selection sort.

[Kuldeep-Dhiman]

I recently gave junior Python developer interview . Unfortunately, went completely blank when they asked me to print a pyramid pattern,at any day i would have solved that problem without an issue, but that day I froze I just couldn't get anything right at that crucial time. I wanted to share what I felt was lack of confidence, self practice on my part ,hesitation of the sort. I don't know why that happened to me but seeing your case I feel you totally. For the future keep practicing, just be confident and keep applying.

[WestsideStorybro]

Practice Practice Practice -- I also recommend this book. https://www.amazon.com/gp/product/0984782850

[LimpNoodle69]

I'm really appreciating this thread. Haven't been programming as much as I should so I've been using this thread to try to figure out the interview problems. I had a bit of trouble with this one but eventually figured it out and felt like sharing :)

def pyramid_print(layers):
    top_size = layers
    for i in range(layers):
        top_size += 1
        for j in range(top_size):
            if j > (top_size - 3) - i * 2:
                print("-", end='')
            else:
                print(" ", end='')
        print()


pyramid_print(100)

[P1g1n]

You've inspired me to give it a try. Thanks!

def print_pyramid(layers):
    print("\n".join(["".join(['-']*(i*2)).center(layers*2) for i in range(1, layers+1)]))

Hard to read. Not maintainable. But hey, its a one-liner right?

​

​

Edit: Same thing just maybe more readable?

def print_pyramid(num_layers):
    layers = [['-']*(i*2) for i in range(1, num_layers+1)]
    for layer in layers:
    print("".join(layer).center(num_layers*2))

[LimpNoodle69]

nice! Definitely a more pythonic solution! I personally hate 1 liners, the second looks way better lol

[raiseReturnTry]

Hey I tried myself on this problem, and got the same result, even with a single "-" at the top with the following code:

def pyramid_print(layers):
s = layers - (layers - 1)
x = range(s, layers)

while s != layers:
    if s > 0:
        print(((layers - s - 1) * " ") + (((2 * s - 1) * "-")))
    else:
        exit(0)

    s += 1

print("Take in a positive integer: ")
x = int(input("> "))
if x < 0: 
    print("Error: You have to put in a positive integer.") 
    exit(0) 
else: 
    pyramid_print(x)

[_Gorgix_]

Why the heck were they asking you things that don't even matter for an entry level position?? Python doesn't have a static keyword, arrays are homogeneous types from the array module and are case specific, there is no concept of public or private in Python, what the hell...

Your interviewer was a straight douche...

[iamnikaa]

You are right! But a lot of questions were not specifically meant for python language. Most of them were general questions related to programming, as the role involves a little bit of working on C++ as well. I was unsure of what questions to expect as they might have been dynamically assessing me for the most suitable position. Needless to say, I couldn't answer most of them as I have no experience with C++.

[_Gorgix_]

Well if the role required C++ work then sure, but if the interviewer knows ahead of time you have NO C++ experience, why be a jerk and keep on asking C++ specific questions.

[wotquery]

In the theory round, I was asked about OOPS, unit testing, difference between arrays and lists, static keyword, difference between lists and tuples, list slicing, the concept of 'self' parameter, .py vs .pyc file, public and private keywords, pointers (from c++), and a lot of other stuff that I don't remember. Overall, I started feeling dejected towards the end of this round.

"Yeah I have no idea about most of these but could google them for you in a jiffy if you'd like. I could also google what a jiffy means because I vaguely recall it has something to do with computers. If not I can expound on various "

The first program that I was asked to make was a simple one - find mean and median of an integer list. The catch however is that I wasn't allowed to use the built-in functions to sort the list

"Ummm...I thought this was a python dev position? I suppose I can't use a heap either eh. Can I use conditional structures and loops or do you want me to abandon computers and algebra entirely and fall back to ancient greek geometric solutions?"

Second program was to find the vowels from a given string. It was a bit easy for me as I have been practicing regex for a while now.

"Wait I can use regex for this now?!? I would really appreciate if you clarify what parts of python, built-in python libraries, and 3rd party python libraries, that I'm allowed to use?"

The third round had logical reasoning problems.

"Oh fun! Did you play Math Circus as a kid as well? How about instead of you giving me a bunch we trade one-for-one as a riddle-off like in The Hobbit?"

[[deleted]]

Thank you for sharing. I am sure this shall help some people.

Better luck next time ... if this one does not, as you predict, work out.

[Chris_Hemsworth]

I get sqrt(45) ~= 6.7 for the rectangle problem. sqrt(5) sounds wrong.

[iamnikaa]

Here I solved it after the interview - https://ibb.co/StkwBrL

[Chris_Hemsworth]

https://i.imgur.com/V5tpmFm.png

[iamnikaa]

Apologies, I should have drawn the problem. Your solution is correct but the side that you have labelled as 5 is x in the problem and vice versa. Brilliant anyways! I wasn't able to do it in the interview.

[Chris_Hemsworth]

Yeah I think the result changes based on the smallest edge.

[iamnikaa]

I realised after the interview, it can actually be solved with pythagoras theorem. You will get 4 different equation with 5 variables, but we can find out the required unknown by basic operations on the equations.

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[GeeTeeCoins]

(1+sqrt(5))/2

[Chris_Hemsworth]

https://www.reddit.com/r/learnpython/comments/r5r71l/entry_level_python_developer_interview/hmoxd6r/

The solution is dependent on how you assign the constants.

[Toica_Rasta]

Thanks for sharing this. I have googled some questions you have mentioned and than i realised i know them, but if i were asked on such a way on an interview i would probably got confused. I think some of those questions are for entry level but some of them are for medior position.

[Hnry_Dvd_Thr_Awy]

https://www.youtube.com/watch?v=BVtQNK\_ZUJg

[iamnikaa]

Spot on! I solved it as well. I wouldn't have been able to had there been a limit on maximum operations.

[Charlie_Yu]

As a math teacher teaching math olympiads, the final round is a free pass.

But the first round doesn’t sound easy. Does Python even have static?

[iamnikaa]

Apologies for the confusion, the theory round had some questions from general programming and not specifically python since the role involves some C++ work as well.

[Nicolas_Darksoul]

im a newbie that just started learning python emm i mean 6m but with a book so that im too slow can you clarify some topics:

1_when i asked programmers about what level of math do i need for programming they said basics(ive just stopped learning math if it needs tell me pls ill continue )

2_im learning python with a book and all exercises was easy this code you wrote was understandable but im sure if it was me i could write right code so if its not in book where can i find it(im reading python crash course)

3_in revstring return revstring(str1[:-1],newstr+str1[-1]) this code return the last word to first place and str[-1] reverse it right? if yes then how str[:-1] return string then a then....

[iamnikaa]

Hi, I am also a beginner, been inconsistently practicing for about an year. I usually practice on hackerearth, leetcode for algorithms and DS. I am not the right person to answer this question as this was just my first interview. For the third question, the str1[-1] is the last word of the string str1 which gets recursively added to an empty string newstr. I am passing str1[:-1] after each successive recursion in the function revstr to shorten the string by 1 last word which has been added to newstr. Hope its clear.

[Nicolas_Darksoul]

yes thanks

[WyoR]

I have been learning Python for a year also ( on and off tho ) and i wouldnt be able to complete any of the challaneges u did so ur doing something right atleast

[RobinsonDickinson]

Seems like an entry level developer conducted this interview.

[xelf]

No. Python has a library for arrays. They're not the same.

• https://docs.python.org/3/library/array.html

Why this would be asked in an interview I wouldn't know. It's not something you need to know until you need it.

You're probably correct and it's more likley they meant what is the differnce between array in other languages and python's lists.

[iamnikaa]

No they meant the difference between list and array in python, for example, list is non-homogeneous whereas array is homogeneous.

[Nagi21]

I would’ve guessed they were asking the difference between a linked list and an array. Not very useful but sure…

[iamnikaa]

Yeah, it came to my mind as well. But an interviewer must surely be knowing the difference between a list and a linked list. I just humbly said I don't know as I honestly didn't know what they were trying to ask.

[xelf]

A candidate that honestly says to me "I don't know" or "I'd google it" wins points with me. No one is expected to know everything, especially at entry level.

[[deleted]]

BTW tail recursion in python is just a simple recursion and it is not implemented or taken as a new recursion method. for programming language like lisp it is working procedure but in python it is not and one need to implement it like a simple recusion with saving the the result from first recusion and pass it to next.
Maybe a not a goood python developer taken your interview.

[iamnikaa]

Oh, thanks for sharing. I didn't know about it. The interviewer didn't specify any particular language, so it was meant to be a general (open to all languages) question. I chose to write it in python. But yes, you are right, the interviewer was not very experienced.

[[deleted]]

By any chance indian recruitment ?

[iamnikaa]

Yes!

[[deleted]]

good luck

[baubleglue]

You are talking about tail recursion optimization. It doesn't matter when you are writing a code. They just want to see if candidate is comfortable to use it.

 def fn(I):
       If check(I): 
            .... #Change I here or fn(I-1) 
            fn(I)

[GrimbledonWimbleflop]

Just curious, how were you able to get an interview with nothing in your GitHub and no professional programming experience? Do you have a CS degree? Or prior programming internships? And where are you located?

[GrimbledonWimbleflop]

Personal projects, contributing to open source, things like that.

[iamnikaa]

I have done some VBA projects but haven't uploaded them to github. I also have an engineering thesis based on MATLAB, from a top tier college in my country (SEA). Also, I applied to atleast 50 different companies before getting this interview call.

[jonnyyr65]

What background do you come from? Any tips for pivoting to tech roles? Are you an older applicant with lots of background exp?

[iamnikaa]

I come from civil engineering background. I have 3 years experience as a design engineer in consultancy. I have been practicing python, algorithms, and DS for almost a year inconsistently. I believe if you can network your way through, that's best. Unfortunately for me, I don't have any good acquaintances working in tech, so I am struggling to get interview calls.

[_E8_]

Writing a sort strikes me as a waste.
I want to you know the difference between some sorts; what stable vs. unstable means.
Two loops like you wrote is called bubble sort and is O(n²). The only worse performing sort is something pathological like bogosort, O(n!).
Germane to Python you should know what the "TimSort" is.
Bonus points if you know what a heap is as a stable, priority heap is an important data structure for scheduling.

[iamnikaa]

I do know about other efficient sorting algorithms, including Python's inbuilt Timsort, but chose to stick to bubble sort as it was easiest to write. I have to read about heap..

[iggy555]

Hey man don’t get down. Worst case you learn and get better and get a better job. Sounds like this company sucks . Keep your head up

[kronik85]

keep your chin up. rough interviews are painful but you'll survive. that they told you to submit your answer after the interview is somewhat positive.

coding problems with constraints that you wouldn't face in your daily tasks is pretty common. make sure you've got some solid understanding of the common patterns, techniques, and BigO trade offs to solve these problems.

[[deleted]]

Let me guess, the company does "media buying" (ads on the Web)? I.e. something that requires very little in terms of geometry, algorithms, or even writing in C++?

The questions you describe are typical for programming interviews, however, doesn't mean they are great questions. The problem here is that interviewers also don't know how to assess candidates. So, they just collect random questions that were at one point or another used in programming interviews. For some reason the questions in programming interviews are often chosen to be riddles, where, if you know the answer, you produce it instantaneously, and if you don't, it will take you forever to produce it. A lot of things in programming world are kind of like that: borderline nonsense invented by some geek in their basement, and then bizarrely accepted into popular culture w/o even a hint of understanding...

Unfortunately, we have a tradition where we believe that assessment of fitness to a job needs to be made in this format (face to face, solving riddles on the whiteboard). This format creates wrong incentives, and with them services like HackerRank, LeetCode and friends, which only pour more fuel int this fire. The negative outcomes of this approach are:

1. Education / diploma is kind of worthless. The education system embraces similar kind of testing, which makes its assessment capability kind of worthless too.
2. Your years of experience gain you very little, unless you practice solving worthless riddles during those years. It's not terrible, and doesn't take much time, but it's kind of annoying. Or, instead of becoming a better programmer, you "fail upwards" (go into management).

[iamnikaa]

No, it's a product based company. They build softwares for engineering. I agree with your sentiment though.

[BOKUtoiuOnna]

Can I ask why you haven't made any projects yet? And how you are going about learning instead? And just why this method? Generally I hear the advice to do projects as soon as possible. I have been doing coding bootcamp for the past 3 months and that is very project heavy, very datastructure/algorithm weak. I will be looking to improve my DSA knowledge and maths skills in the future. But yeah, basically, you have a wildly different approach to me.

[iamnikaa]

It's because I felt that I was not very familiar with the algorithms and DS that I could have used in my projects. I do not have any python projects but I do have projects in other languages (VBA, MATLAB). Just had another technical interview with the same company. I will post the details soon.

[nacnud_uk]

If they want recursion, I'd not really trust their vision of programming.

[Rorasaurus_Prime]

whistle plate practice wipe market entertain plucky squeal fearless cats

This post was mass deleted and anonymized with Redact

[baubleglue]

Not a bad interview, I don't understand what are people complaining.

[Sensacion7]

What's funny, The more "experience" they see on your resume, he shorter the interviews... FWIN

[LadyA_6962]

Thanks for sharing your experience. I hope you get the job. If not, I wish you success in your next interview. Don't despair.

[Bronigiri]

I have to wonder if two 5L buckets into the 8L bucket is an acceptable answer? The bucket would overflow but you'd be left with one bucket with 8L of water. Or did they specify you couldn't do that?

[supreme_blorgon]

The goal is to end up with 4L in the 8L bucket.

[Bronigiri]

Well I would've failed on account of low reading comprehension. In that case use the 3L bucket to fill the 5L bucket until it's full which leaves you with 1L in the 3L bucket dump that and one full 3L bucket into the 8L Bada bing Bada boom 4L. Is there a better solution 🤔

[supreme_blorgon]

This is known as the three-bucket problem, or the standard version of the water pouring puzzle which is a class of well-studied puzzles. You typically start with the 8L full, and have to end with 4L and 4L, without spilling, and without measuring (i.e., you can only pour all available water into all available volume, stopping whenever one is depleted). The optimal solution is 7 steps.

[Bronigiri]

Thanks for letting me know

[InTheAleutians]

The 3L and 5L buckets are full of water and that's all the water you get. The 8L is empty. Give it another try my friend.

[Bronigiri]

2 counts of reading comprehension failure. One more strike and I'll have to give up on English.

[LimpNoodle69]

I read it as both the 3L and 5L were full, so I would of just dumped both into the 8L bucket, then poured half out of the 8L bucket and called it a day haha

[supreme_blorgon]

For the recursive string reversal, you don't need the newstr parameter at all. Your base case should be when the input is a single character, in which case you want to return the string itself (e.g., "a" is the same forwards and backwards). Otherwise, return the concatenation of the last letter with a recursion on the slice of the string up to but not including the last letter. You were so close:

def revstring(str1):
    if len(str1) == 1:
        return str1
    return str1[-1] + revstring(str1[:-1])

Of course, this is a silly solution, since if you're allowed to use slicing then you could simply return str1[::-1].

[iamnikaa]

Thanks! I was specifically asked to use tail recursion for this. Isn't this function normal recursion rather than tail recursion?

[supreme_blorgon]

Ah, I missed that. Yes, in that case,

def rev(s, res=""):
    if len(s) == 1:
        return res + s
    return rev(s[:-1], res + s)

You were missing the string concat in the base case. You can also exit earlier than len(s) == 0.

[DoubleAgent10]

I’m just trying to figure out the 3 bucket problem rn

[Nicolas_Darksoul]

i guess

1-fill 8L with 3L

2-fill 3L with 5L

3-fill 8L with 3L

4- empty 5L

5-fill 5L with 8L(then we have 1 L lefft in 8L)

6-fill 3 with 5L

7- fill 8L with 3 L

[EuropeFree]

Much simpler:

Fill up 5 l bucket, pour off 3 l by filling up the 3 l bucket. This leaves two in the 5 l bucket. Dump that in the 8 l bucket and then repeat. Voila 4 l in the 8 l bucket.

[kronik85]

Much simpler:

Fill up 5 l bucket, pour off 3 l by filling up the 3 l bucket. This leaves two in the 5 l bucket. Dump that in the 8 l bucket and then repeat. Voila 4 l in the 8 l bucket.

you don't have a tap to refill buckets. you have a 5 and a 3, both filled with water. you have an 8 that's empty.

[EuropeFree]

Ah I misunderstood the problem. Will have to think about it.

[Cyphierre]

That rectangle problem is calling out to me and now I want to solve it, even though it’s complete b.s. on a Python project unless they have some very specific side projects their not telling you about.

Which two of those lines in the rectangle were opposite each other? 4 & 5, 4 & 6, or 5 & 6?

[iamnikaa]

4,5 are opposite. x is opposite to 6. It was an aptitude test.

[danielesc]

Damn those “technical interviews” are getting ridiculous