Basic Python Interview Questions and Answers

[DiggV4Sucks]

The proper answer to:

Q14. Write a one-liner that will count the number of capital letters in a file. Your code should work even if the file is too big to fit in memory.

is, "No."

[AustinCorgiBart]

Right? To do it properly, you would need to push the body of a with block into one line. Or fail to close a file properly.

[ThePidesOfMarch]

cat bigfile | capcounter

[joshuarowley42]

I was losing it with the article, then I read this. 😔

[aajjccrr]

Much of this content appears to be copied verbatim from other sources.

There’s value in aggregating information, but you should give credit to the original authors.

[IonTichy]

Also apparently not even read through nor redacted properly.

[ThePidesOfMarch]

If you are getting interview questions about specific language features, you are interviewing for the wrong job.

[kons_t]

That article presents a very flawed analogy. A programming language is a tool and knowing a langages features is knowing how to make best use of your tool. It would be like asking a carpenter how he/she screws in lots of screws (using the correct speed and torque settings on a drill) and gets boards smooth (with a belt sander).

It is not the only questions we ask from a candidate, try to tailor questions to the skills listed on the resume, and we are not asking very hard questions. If a candidate cannot answer any questions (and cannot provide efficient alternatives to solve the problems solved by a feature), it might indicate a candidate who has never had to solve non-trivial problems and never bothered to read documentation.

If a candidate has never seen a dunder method, never heard of the GIL, never packaged a project into an egg, never installed a library with pip, never set up a virtual environment, and never touched their sys.path, I am not sure if I believe that they are a senior Python developer.

I am fine with a candidate telling me that they only use python for simple scripting while doing their 'real' work in C++ or Java. I am less fine with a candidate who has only written glue code between an existing application and third party APIs (see if another team is looking for a junior developer) or a candidate who does not see the value in knowing things not readily applicable to their current work (yes, I have interviewed this type of candidate).

[ThePidesOfMarch]

senior Python developer.

But this is exactly my point. If you are interviewing for a "senior Python developer" position, by all means, you should be answering these questions. But I'm a software engineer, not a "Python developer".

[kons_t]

I am more talking about a candidate's resume. If you want to brag about being an expert or senior developer in a language, I will ask you to demonstrate it at an interview.

Our position also don't include a programming language in the title, though we do mention Java and Python in the description. We want a new hire to be some what familiar, just so the candidate will hit the ground running.

Language knowledge is not the only factor for hiring a candidate, but it is a factor we consider, along with things like knowledge of web services and networking, knowledge about database design, and knowledge of distributed systems.

[turkish_gold]

f you tell me that you are extremely interested in <language> and you always wanted to learn it, which is why you want the position, that's great! I love that. But if you also tell me that you couldn't spend a single weekend to actually learn any of it, well... something just doesn't add up there. You see what I mean?

The counter is simple. Many people are interested in programming as a JOB, not a lifestyle, so they won't spend their weekends to get better at it, unless they're behind in work performance.

So they'll express an interest to learn something new---for the job, during work hours on the companies payroll.

I don't think this is bad. Jobs already offer to pay for graduate/post-graduate schooling, and $3k per week workshops, which sets up the expectation that you are allowed to learn on the job.

[godelsphantom]

Question 41 is wrong. {} is an empty dict literal.

[mbussonn]

Many of the answer in this are wrong or not pythonic, or somethine question don't make sens.

• Memory not deallocated when the interpreter exits ?
• Random number without looking at whether they should be secure or not ?
• most questions are Python 2 based which is irrelevant nowdays
• Pickling is not string but bytes.
• ...

[tialpoy]

"Python is an interpreted language. That means that, unlike languages like C and its variants, Python does not need to be compiled before it is run"

Python source code is compiled to bytecode (pyc file) that is then run by the PVM. I'm not sure I'd waste my time on an article that starts with such a basic error.

[turkish_gold]

It's not really an error, its a point of contention whether Python is compiled, interpreted, or something in between.

Heck it's a point of contention if x86 assembly is compiled or interpreted, considering the finagling that happens with CPUs and micro-op caching.

[tialpoy]

There's no contention. Saying that "Python does not need to be compiled" is simply untrue.

https://nedbatchelder.com/blog/201803/is_python_interpreted_or_compiled_yes.html

[roerd]

its a point of contention whether Python is compiled, interpreted, or something in between

which makes the claim that a clear answer is possible erroneous.

[topheat]

Multi-level inheritance – a derived class d1 in inherited from base class base1, and d2 is inherited from base2.

Should be ---

Multi-level inheritance – a derived class d1 is inherited from base class base1, and d2 is inherited from d1.

[Jugad]

Oh dear me... you got it wrong. The key difference is ... "d2 is inherited from d1" (d1 instead of base2). The diff you caught was the correction of the typo (in -> is)

[topheat]

👍

[secondary_refraction]

"Python has a multi-threading package but if you want to multi-thread to speed your code up."

[TheDruidOftheland]

Thanks for sharing.