Functions And Lambda Expressions
This chapter will focus on the functional aspects of Python. We’ll start by defining functions with a variable amount of positional as well as keyword arguments. Next, we’ll cover lambda functions and in which cases they can be helpful. Especially, we’ll see how to use them with such functions as map, filter, and reduce. Finally, we’ll recall what is recursion and how to correctly implement one.
Sample Google Python Interview Questions For Practice
Here are some Google Python interview questions. Ensure you can solve them before your interview:
Preparing For Programming Interview With Python
I have been preparing for a few interviews in tech/finance companies . I am a final year computer science PhD student at National University of Singapore, and my PhD did not have much programming component to it. While preparing, I have gathered a few pointers for going over again and again before the interview so when I say general tips I mean tips for me to remember. Hope it helps.
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Be Familiar With The Different Libraries
Python has a wide range of libraries that can be used for different purposes. When preparing for an interview, make sure you are familiar with the most popular libraries as well as those that are relevant to the position youre applying for. For example, if youre applying for a data science position, brush up on your Pandas and NumPy skills. Interview questions on python libraries is an important topic for interviewees. This is because it helps to assess your knowledge in using the different python libraries. The interviewer can ask questions about the most popular python libraries, the functions of these libraries, and how to use them. You should be able to explain the functions of the different python libraries and show that they understand how to use them. The candidate should also be able to give examples of how they have used these libraries in their work.
Here are few questions you would want to get familiar with:
- What are some of the most popular Python third party libraries you have worked with?
- What is the purpose of the os library? What is the difference between the os and os.path modules?
- What functions are contained in the math module?
- How would you go about accessing the re module?
- What is contained in the collections module?
- What are some features of the pandas library?
- How would you use the matplotlib library to plot a line graph?
What Are Some Good Questions To Ask The Interviewer
Companies are always looking for talented individuals who will stay with the company for a long time and provide as much value as possible. Some good questions to show your potential in this area would be:
1. Where do you see the company in five years?2. What opportunities are there for training and progression within the company?3. What would my daily responsibilities look like?
Since youre hereNo one wakes up knowing how to code they learn how to code. Tens of thousands of students have successfully learned with our courses, like our Software Engineering Bootcamp. If youre a total newbie, our Software Engineering Career Track Prep Course will be a perfect fit. Lets do this!
About Monica J. White
Monica is a journalist with a lifelong interest in technology, from PC hardware to software and programming. She first started writing over ten years ago and has made a career out of it. Now, her focus is centered around technology and explaining complex concepts to a broader audience.
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What You Cant Code Up A Recursive Descent Parser On A Whiteboard In 75 Minutes How Dare Youeven Apply For This Job
Yeah, its one of the things that sucks about our industry
Personally, I believe that 80-90% of the questions that you get asked during a typical coding interview have very little to do with your real performance on the job.
But unfortunately these interviews arent going to go away over night.
If you want a well-paid job as a software developer, youre likely going to encounter some coding quiz as part of your interviewing experience.
For the foreseeable future, interviewers are going to keep squeezing you through the same processes and will keep asking you those same questions
And if youre like me, theres a pretty slim chance youll pass an interview like that without some serious prep workeither to learn the right skills or to refresh your memory.
Alright, that all sounds pretty glum, no?
But heres what you need to realize:
Python Framework Interview Questions
Q.53. Differentiate between Django, Pyramid, and Flask.
These are three major frameworks in Python. Here are the differences:
- We can also use Django for larger applications. It includes an ORM.
- Flask is a microframework for a small platform with simpler requirements. It is ready to use and you must use external libraries.
- The pyramid is for larger applications. It is flexible and you can choose the database, the URL structure, the templating style, and much more. It is also heavily configurable.
Q.54. Explain the Inheritance Styles in Django.
Talking on inheritance styles, we have three possible-
- Abstract Base Classes- For the parent class to hold information so we dont have to type it out for each child model
- Multi-table Inheritance- For subclassing an existing model and letting each model have its own database
- Proxy Models- For modifying the models Python-level behavior without having to change its fields
Q.55. What is Flask- WTF? Explain its features.
Flask-WTF supports simple integration with WTForms. It has the following features-
- Integration with wtforms
- Secure form with csrf token
- File upload compatible with Flask uploads
Q.56. What is Flask?
Python Flask, as weve previously discussed, is a web microframework for Python. It is based on the Werkzeug, Jinja 2 and good intentions BSD license. Two of its dependencies are Werkzeug and Jinja2. This means it has around no dependencies on external libraries. Due to this, we can call it a light framework.
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Practice With Mock Interviews
The steps mentioned above can be rehearsed over and over again until you have fully internalized them and they become second nature to you. A good way to practice is by partnering with a friend and taking turns to interview each other.
A great resource for preparing for coding interviews is interviewing.io. This platform provides free and anonymous practice interviews with Google and Facebook engineers, which can lead to real jobs and internships.
Doing well in mock interviews will unlock the jobs page for candidates, and allow them to book interviews with top companies like Uber, Lyft, Quora, Asana, and more. For those who are new to coding interviews, a demo interview can be viewed on this site. Note that this site requires users to sign in.
I have used interviewing.io, both as an interviewer and an interviewee. The experience was great. Aline Lerner, the CEO and co-founder of interviewing.io, and her team are passionate about revolutionizing the process for coding interviews and helping candidates improve their interview skills.
She has also published a number of coding interview-related articles on the interviewing.io blog. I recommend signing up as early as possible with interviewing.io, even though it’s in beta, to increase the likelihood of receiving an invite.
How Are Arguments Passed By Value Or By Reference In Python
- Pass by value: Copy of the actual object is passed. Changing the value of the copy of the object will not change the value of the original object.
- Pass by reference: Reference to the actual object is passed. Changing the value of the new object will change the value of the original object.
In Python, arguments are passed by reference, i.e., reference to the actual object is passed.
defappendNumber: arr.appendarr = print #Output: => appendNumberprint #Output: =>
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While Importing Data From Different Sources Can The Pandas Library Recognize Dates
Yes, they can, but with some bit of help. We need to add the parse_dates argument while we are reading data from the sources. Consider an example where we read data from a CSV file, we may encounter different date-time formats that are not readable by the pandas library. In this case, pandas provide flexibility to build our custom date parser with the help of lambda functions as shown below:
import pandas as pdfrom datetime import datetimedateparser = lambda date_val: datetime.strptimedf = pd.read_csv
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What Is Main Function In Python How Do You Invoke It
In the world of programming languages, the main is considered as an entry point of execution for a program. But in python, it is known that the interpreter serially interprets the file line-by-line. This means that python does not provide main function explicitly. But this doesn’t mean that we cannot simulate the execution of main. This can be done by defining user-defined main function and by using the __name__ property of python file. This __name__ variable is a special built-in variable that points to the name of the current module. This can be done as shown below:
defmain:printif __name__=="__main__": main
How Do You Copy An Object In Python
In Python, the assignment statement does not copy objects. Instead, it creates a binding between the existing object and the target variable name. To create copies of an object in Python, we need to use the copy module. Moreover, there are two ways of creating copies for the given object using the copy module –
Shallow Copy is a bit-wise copy of an object. The copied object created has an exact copy of the values in the original object. If either of the values is a reference to other objects, just the reference addresses for the same are copied.Deep Copy copies all values recursively from source to target object, i.e. it even duplicates the objects referenced by the source object.
from copy import copy, deepcopylist_1 = , 4]## shallow copylist_2 = copy list_2 = 7list_2.appendlist_2 # output => , 7]list_1 # output => , 4]## deep copylist_3 = deepcopylist_3 = 8list_3.appendlist_3 # output => , 8]list_1 # output => , 4]
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Python Coding Interview Questions On Trees
Take a look at the top Python Data Structures Interview Questions and Answers for practice.
Debug With Breakpoint Instead Of Print
You may have debugged a small problem by adding to your code and seeing what was printed out. This approach works well at first but quickly becomes cumbersome. Plus, in a coding interview setting, you hardly want peppered throughout your code.
Instead, you should be using a debugger. For non-trivial bugs, its almost always faster than using print, and given that debugging is a big part of writing software, it shows that you know how to use tools that will let you develop quickly on the job.
If youre using Python 3.7, you dont need to import anything and can just call breakpoint at the location in your code where youd like to drop into the debugger:
# Some complicated code with bugsbreakpoint
Calling breakpoint will put you into pdb, which is the default Python debugger. On Python 3.6 and older, you can do the same by importing pdb explicitly:
Like breakpoint, pdb.set_trace will put you into the pdb debugger. Its just not quite as clean and is a tad more to remember.
There are other debuggers available that you may want to try, but pdb is part of the standard library, so its always available. Whatever debugger you prefer, its worth trying them out to get used to the workflow before youre in a coding interview setting.
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Faqs On Python Data Science Interview Questions
Q1. How do I prepare for Python data science interview questions?
While there is no fixed way to prepare for Python data science interview questions, having a good grasp of the basics can never go wrong. Some important topics you should keep in mind for Python interview questions for data science are: basic control flow for loops, while loops, if-else-elif statements, different data types and data structures of Python, Pandas and its various functions, and how to use list comprehension and dictionary comprehension.
Q2. Will Python be allowed in coding interviews?
While the simple answer is yes, it can vary from company to company. Python can be allowed in coding rounds, and several companies even use platforms such as HackerRank to conduct Python data science interview questions.
Q3. Explain Arrays in Python data science interview questions.
Arrays are a data structure, just like lists. With a number of objects of different data types, Python arrays can be repeated and have several built-in functions to handle them. Such conceptual questions play a vital role in Python data science interview questions. So keep this in mind when preparing.
Q4. Which resources to use to prepare for Python data science interview questions?
Some free resources to prepare for Python data science interview questions are CodeAcademy, FreeCodeCamp, DataCamp, Udacity, and Geeks for Geeks.
Q5. How long does it take to learn Python?
Differentiate Between A Package And A Module In Python
The module is a single python file. A module can import other modules as objects. Whereas, a package is the folder/directory where different sub-packages and the modules reside.
A python module is created by saving a file with the extension of .py. This file will have classes and functions that are reusable in the code as well as across modules.
A python package is created by following the below steps:
- Create a directory and give a valid name that represents its operation.
- Place modules of one kind in this directory.
- Create __init__.py file in this directory. This lets python know the directory we created is a package. The contents of this package can be imported across different modules in other packages to reuse the functionality.
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What Are Decorators In Python
in Python are essentially functions that add functionality to an existing function in Python without changing the structure of the function itself. They are represented the @decorator_name in Python and are called in a bottom-up fashion. For example:
# decorator function to convert to lowercasedeflowercase_decorator:defwrapper: func = function string_lowercase = func.lowerreturn string_lowercasereturn wrapper# decorator function to split wordsdefsplitter_decorator:defwrapper: func = function string_split = func.splitreturn string_splitreturn wrapper@splitter_decorator # this is executed next@lowercase_decorator # this is executed firstdefhello:return'Hello World'hello # output =>
The beauty of the decorators lies in the fact that besides adding functionality to the output of the method, they can even accept arguments for functions and can further modify those arguments before passing it to the function itself. The inner nested function, i.e. ‘wrapper’ function, plays a significant role here. It is implemented to enforce encapsulation and thus, keep itself hidden from the global scope.
# decorator function to capitalize namesdefnames_decorator:defwrapper: arg1 = arg1.capitalize arg2 = arg2.capitalize string_hello = functionreturn string_helloreturn wrapper@names_decoratordefsay_hello:return'Hello ' + name1 + '! Hello ' + name2 + '!'say_hello # output => 'Hello Sara! Hello Ansh!'
What Is A Coding Interview
A coding interview provides you with a chance to demonstrate your technical skills in a practical environment. The interviewer gives you a problem to solve and asks you to write working code to solve that problem. The interviewer may ask questions as you are coding about your thought processes.
In addition to the hands-on portion of the interview, you also answer questions about your experience and training, and you may also answer behavioral questions. Depending on where the interview takes place, you could complete the coding portion on your own computer at home or at the job site. Sometimes, the hiring manager may send the coding test before inviting you in for an interview. Other times, you may only see the test once youve begun the interview.
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