How To Crack Python Coding Interview

How To Practice Python Coding For Interviews

Python programming is a widely used high-level, general-purpose, interpreted, and dynamic programming language for modern application development. If you are a novice programmer, you must attend any good Python training course and practice Python coding every day with different concepts. Participate in forums, coding challenges, hackathons, bug bounty programs, and learn python coding interview questions here.

How To Crack Pdf Files In Python

pip install pikepdf

pip install tqdm

tqdm

Below is the full implementation:

Cracking The Coding Interview Book Pdf Free Download

Cracking the Coding Interview, 6th Edition is here to help you through this process, teaching you what you need to know and empowering you to give your best. I have educated and interviewed hundreds of software engineers. The result is this book.

Learn how to uncover the hidden tricks and details of a question, learn how to break a problem down into manageable chunks, develop techniques to free yourself when you get stuck, learn computer basics, and practice. questions and solutions.

These interview questions are real they are not taken from computer textbooks. They reflect what’s really in demand in the best companies, so you can be as prepared as possible. WHAT’S INSIDE?

189 programming interview questions, ranging from the basics to the most delicate algorithm problems.An overview of how to derive each solution, so you can learn how to do it yourself.Tips on how to solve each of the 189 questions, just like what you’d get in a real interview.Five proven strategies for dealing with algorithm questions, so you can solve questions you’ve never seen.Extensive coverage of essential topics, such as big O time, data structures and basic algorithms.A behind-the-scenes look at how top companies like Google and Facebook hire developers.Techniques for Preparing and Succeeding on the Soft Side of the Interview: Behavioral Questions.For Interviewers and Companies: Details on what makes a good interview application and hiring process good.

Also Check: Interview Questions To Ask A Cfo

About Gayle Laakmann Mcdowell

Gayle is also the founder and CEO of CareerCup.com.

She put together Cracking the Coding Interview for anyone who wants to be prepared when interviewing at a FAANG company.

Cracking the Coding Interview is broken down into two sections:

The Interview Process

• The Facebook Interview
• The Palantir Interview

McDowell gives a detailed rundown of what to expect for each companys recruiting process, how to prepare and what is unique about their interview.

Lets take her Facebook interview as an example.

Interview process: You can expect a phone screen that will involve coding via an online document editor. Then you may have a series of coding and algorithm assignments. Following that, an on-site interview.

No detail is spared in explaining every step of the process.

But note: According to McDowell, Facebook prefers fast, entrepreneurial, and accurate coders. They also interview for non-specific departments. If hired, youll go through their bootcamp for their code base, get mentorship from senior devs, then earn flexibility in your choosing projects.

What Are Iterators In Python

• An iterator is an object.
• It remembers its state i.e., where it is during iteration
• __iter__ method initializes an iterator.
• It has a __next__ method which returns the next item in iteration and points to the next element. Upon reaching the end of iterable object __next__ must return StopIteration exception.
• It is also self-iterable.
• Iterators are objects with which we can iterate over iterable objects like lists, strings, etc.

classArrayList:def__init__:       self.numbers = number_listdef__iter__:       self.pos = 0return selfdef__next__:if):           self.pos += 1return self.numberselse:raise StopIterationarray_obj = ArrayListit = iterprint) #output: 2print) #output: 3print)#Throws Exception#Traceback :#...#StopIteration

Recommended Reading: Best System Design Interview Prep

What Are Generators In Python

Generators are functions that return an iterable collection of items, one at a time, in a set manner. Generators, in general, are used to create iterators with a different approach. They employ the use of yield keyword rather than return to return a generator object.Let’s try and build a generator for fibonacci numbers –

## generate fibonacci numbers upto ndeffib:   p, q = 0, 1while:yield p       p, q = q, p + qx = fib    # create generator object ## iterating using __next__, for Python2, use nextx.__next__    # output =>  0x.__next__    # output =>  1x.__next__    # output =>  1x.__next__    # output =>  2x.__next__    # output =>  3x.__next__    # output =>  5x.__next__    # output =>  8x.__next__    # error## iterating using loopfor i in fib:print    # output =>  0 1 1 2 3 5 8

Sort Complex Lists With Sorted

Plenty of coding interview questions require some kind of sorting, and there are multiple valid ways you can sort items. Unless the interviewer wants you to implement your own sorting algorithm, its usually best to use sorted.

Youve probably seen the most simple uses of sorting, such as sorting lists of numbers or strings in ascending or descending order:

> > > sorted> > > sorted

Its worth knowing about the optional keyword argument key that lets you specify a function that will be called on every element prior to sorting. Adding a function allows custom sorting rules, which are especially helpful if you want to sort more complex data types:

> > > animals=> > > sorted

By passing in a lambda function that returns each elements age, you can easily sort a list of dictionaries by a single value of each of those dictionaries. In this case, the dictionary is now sorted in ascending order by age.

get_unique_words stores values in a list then converts the list into a set:

> > > defget_unique_words:... words=... for_inrange:... words.append)... returnset> > > get_unique_words

This approach isnt terrible, but it unnecessarily creates a list and then converts it to a set. Interviewers almost always notice this type of design choice.

Worse Approach

To avoid converting from a list to a set, you now store values in a list without using any other data structures. You then test for uniqueness by comparing new values with all elements currently in the list:

Good Approach

Also Check: Interview With Cfo

Cracking Python Interview Questions On Programming

• Answering Approach to python programming interview questions
• Confidence in resolving the python programming questions in the interviews. Confidence in clearing interviews.
• Ability to explain each and every line in the python program
• Ability to understand each and every line of the python code base
• Anybody who takes up this course will be able to crack python interviews on programming

What Are Global Protected And Private Attributes In Python

• Global variables are public variables that are defined in the global scope. To use the variable in the global scope inside a function, we use the global keyword.
• Protected attributes are attributes defined with an underscore prefixed to their identifier eg. _sara. They can still be accessed and modified from outside the class they are defined in but a responsible developer should refrain from doing so.
• Private attributes are attributes with double underscore prefixed to their identifier eg. __ansh. They cannot be accessed or modified from the outside directly and will result in an AttributeError if such an attempt is made.

Don’t Miss: Design Interview Preparation

What Is Pass In Python

The pass keyword represents a null operation in Python. It is generally used for the purpose of filling up empty blocks of code which may execute during runtime but has yet to be written. Without the pass statement in the following code, we may run into some errors during code execution.

defmyEmptyFunc:# do nothingpassmyEmptyFunc    # nothing happens## Without the pass keyword# File "< stdin> ", line 3# IndentationError: expected an indented block

Use List Comprehensions Instead Of Map And Filter

I think dropping filter and map is pretty uncontroversial

Guido van Rossum, Pythons creator

He may have been wrong about it being uncontroversial, but Guido had good reasons for wanting to remove map and filter from Python. One reason is that Python supports list comprehensions, which are often easier to read and support the same functionality as map and filter.

Lets first take a look at how wed structure a call to map and the equivalent list comprehension:

> > > numbers=> > > defsquare:... returnx*x...> > > list)> > > 

Both approaches, using map and the list comprehension, return the same values, but the list comprehension is easier to read and understand.

Now we can do the same thing for the filter and its equivalent list comprehension:

> > > defis_odd:... returnbool...> > > list)> > > 

Like we saw with map, the filter and list comprehension approaches return the same value, but the list comprehension is easier to follow.

Developers who come from other languages may disagree that list comprehensions are easier to read than map and filter, but in my experience beginners are able to pick up list comprehensions much more intuitively.

Either way, youll rarely go wrong using list comprehensions in a coding interview, as it will communicate that you know whats most common in Python.

Don’t Miss: Interview Attire Women

What Are Good Python Interview Questions

Basic Python Interview Questions

• Q1. What is the difference between list and tuples in Python?
• Q2. What are the key features of Python?
• Q3. What type of language is python?
• Q4.Python an interpreted language. Explain.
• Q5.What is pep 8?
• Q6. How is memory managed in Python?
• Q7. What is namespace in Python?
• Q8.

Format Strings With F

Python has a lot of different ways to handle string formatting, and it can be tricky to know what to use. In fact, we tackle formatting in depth in two separate articles: one about string formatting in general and one specifically focused on f-strings. In a coding interview, where youre using Python 3.6+, the suggested formatting approach is Pythons f-strings.

f-strings support use of the string formatting mini-language, as well as powerful string interpolation. These features allow you to add variables or even valid Python expressions and have them evaluated at runtime before being added to the string:

> > > defget_name_and_decades:... returnf"My name is  and I'm  decades old."...> > > get_name_and_decadesMy name is Maria and I'm 3.10000 decades old.

The f-string allows you to put Maria into the string and add her age with the desired formatting in one succinct operation.

The one risk to be aware of is that if youre outputting user-generated values, then that can introduce security risks, in which case Template Strings may be a safer option.

Also Check: Interview Attire Womens

What Is Pickling And Unpickling

Python library offers a feature – serialization out of the box. Serializing an object refers to transforming it into a format that can be stored, so as to be able to deserialize it, later on, to obtain the original object. Here, the pickle module comes into play.

Pickling:

• Pickling is the name of the serialization process in Python. Any object in Python can be serialized into a byte stream and dumped as a file in the memory. The process of pickling is compact but pickle objects can be compressed further. Moreover, pickle keeps track of the objects it has serialized and the serialization is portable across versions.
• The function used for the above process is pickle.dump.

Unpickling:

• Unpickling is the complete inverse of pickling. It deserializes the byte stream to recreate the objects stored in the file and loads the object to memory.
• The function used for the above process is pickle.load.

Note:Python has another, more primitive, serialization module called , which exists primarily to support .pyc files in Python and differs significantly from the pickle.

Q94 How Can You Get The Google Cache Age Of Any Url Or Web Page

Ans: Use the following URL format:

http://webcache.googleusercontent.com/search?q=cache:URLGOESHERE

Be sure to replace URLGOESHERE with the proper web address of the page or site whose cache you want to retrieve and see the time for. For example, to check the Google Webcache age of edureka.co youd use the following URL:

http://webcache.googleusercontent.com/search?q=cache:edureka.co

You May Like: Questions To Ask A Cfo In An Interview

Python Coding Question: 35+ Python Interview Coding Questions

It is challenging for freshers to find most asked python programming coding interview questions that commonly asked in interviews.

Here We have collected 35+ Most asked python coding Interview Questions that are recommended by Engineers of MNCs.

This coding question of Java Programming will help you to crack the coding interview rounds.

Coding Programs are like you have given some operations to perform on numbers, strings, arrays, or on linked lists.

Below are the Python programs which mostly asked in a coding round, which are categorized in section wise. Prepare each variety of coding questions, which is very important and will help you crack your coding rounds.

Q84 Explain What Flask Is And Its Benefits

Ans: Flask is a web microframework for Python based on Werkzeug, Jinja2 and good intentions BSD license. Werkzeug and Jinja2 are two of its dependencies. This means it will have little to no dependencies on external libraries. It makes the framework light while there is a little dependency to update and fewer security bugs.

A session basically allows you to remember information from one request to another. In a flask, a session uses a signed cookie so the user can look at the session contents and modify. The user can modify the session if only it has the secret key Flask.secret_key.

Read Also: How To Prepare System Design Interview

Surviving The Whiteboard Interview

Surviving the Whiteboard Interview by William Gant addresses many of the fears we have about coding interviews such as public speaking and coding interview questions.

But it aims to quell those fears by getting you prepared to the maximum for your coding interview.

First youll learn about psychological roadblocks at whiteboard interviews. Then youll learn how to overcome those roadblocks.

In addition, youll learn about some soft skills youll need to entice the interviewers. Plus youll learn how to spruce up your resume.

But most importantly, youll learn how to get through and pass your whiteboard interview.

Is Cracking The Coding Interview Worth It In 2022

Those of us with FAANG-level coding aspirations also have FAANG-level uncertainty. There are plenty of variables to consider. From submitting your application to getting a callback, the first interview to the third, you want to present your experience with confidence.

Working for one of these places is a fantasy. A Dream. But could it become a reality? Your reality?

Quite possibly. But you have to pass the first interview .

So you should be prepared to answer their questions. And be ready to solve their coding problems in real time.

This post contains affiliate links. I may receive compensation if you buy something. Read my disclosure for more details.

Recommended Reading: Best Interview Clothes For A Woman

Q105 Why Are Local Variable Names Beginning With An Underscore Discouraged

a) they are used to indicate a private variables of a class b) they confuse the interpreter c) they are used to indicate global variables d) they slow down execution

Answer: a) they are used to indicate a private variable of a class

As Python has no concept of private variables, leading underscores are used to indicate variables that must not be accessed from outside the class.

Explain Doubly Linked Lists

• Doubly linked lists are categorized as a special type of linked list in which traversal across the data elements can be done in both directions.
• This is made possible by the presence of two links in every node, one that links to the node next to it and another that connects to the node before it.

Fig: Doubly Linked List

Read Also: How To Prepare System Design Interview

Have The Understanding To Comprehend And Solve Problems

The willingness to comprehend a problem, use case, potential to be applied in software, then convert it into code will set you apart from the crowd. This necessitates the use of both hard and soft skills. You must be able to carefully listen to the function requirement or bug description and recognize the relevant information, as well as ask follow-up questions to elicit additional key details. If you wish to crack Python developer interview, you must make sure to inculcate problem-solving and analytical skills as theyd help you easily handle challenging scenarios.

Know Python Developer Annual Salary and Job Profile details here

Are There Any Tools For Identifying Bugs And Performing Static Analysis In Python

Yes, there are tools like PyChecker and Pylint which are used as static analysis and linting tools respectively. PyChecker helps find bugs in python source code files and raises alerts for code issues and their complexity. Pylint checks for the modules coding standards and supports different plugins to enable custom features to meet this requirement.

Recommended Reading: What To Wear For An Interview Women

How To Install Python

To Install Python, first go to Anaconda.org and click on Download Anaconda. Here, you can download the latest version of Python. After Python is installed, it is a pretty straightforward process. The next step is to power up an IDE and start coding in Python. If you wish to learn more about the process, check out this Python Tutorial.

Save Memory With Generators

List comprehensions are convenient tools but can sometimes lead to unnecessary memory usage.

Imagine youve been asked to find the sum of the first 1000 perfect squares, starting with 1. You know about list comprehensions, so you quickly code up a working solution:

> > > sum333833500

Your solution makes a list of every perfect square between 1 and 1,000,000 and sums the values. Your code returns the right answer, but then your interviewer starts increasing the number of perfect squares you need to sum.

At first, your function keeps popping out the right answer, but soon it starts slowing down until eventually the process seems to hang for an eternity. This is the last thing you want happening in a coding interview.

Whats going on here?

Its making a list of every perfect square youve requested and summing them all. A list with 1000 perfect squares may not be large in computer-terms, but 100 million or 1 billion is quite a bit of information and can easily overwhelm your computers available memory resources. Thats whats happening here.

Thankfully, theres a quick way to solve the memory problem. You just replace the brackets with parentheses:

> > > sum))333833500

Swapping out the brackets changes your list comprehension into a generator expression. Generator expressions are perfect for when you know you want to retrieve data from a sequence, but you dont need to access all of it at the same time.

Read Also: Best Interview Attire For A Woman