Data Engineer Interview: Coding Exercises
These questions will help you practice for the coding exercise portion of the interview. Typically, youll be given some information – like a data set – and asked to write Python code to solve the problem. These types of questions can test beginner Python skills, all the way up to advanced sequences and functions in Python.
Q1. Given a string, write a function recurring_char to find its first recurring character. Return None if there is no recurring character.
Note: Treat upper and lower case letters as distinct characters. You may assume the input string includes no spaces.
example:
input = "interviewquery"output = "i"input = "interv"output = "None"
Hint: We know we have to store a unique set of characters of the input string and loop through the string to check which ones occur twice.
Given that we have to return the first index of the second repeating character, we should be able to go through the string in one loop, save each unique character, and then just check if the character exists in that saved set. If it does, return the character.
Q2. Given a dictionary consisting of many roots and a sentence, write a function replace_words to stem all the words in the sentence with the root forming it. If a word has many roots that can form it, replace it with the root with the shortest length.
Explain Stack Along With Its Applications
A stack is a data structure in which elements are placed one on top of the other and additions and deletions can occur only at the top. Stacks can be used in the following applications:
- A stack can be used in applications where users are enabled to backtrack on previous operations by one step or move forward with a new operation.
- The process of reversing the characters in a string can be completed by placing them in a stack and using the pop operation.
Q10 Explain Slicing In Python
Slicing is the mechanism to choose a range of items from sequence types such as lists, tuples, and strings. For example, slicing a list refers to selecting a specific portion or a subset of the list for some function, and the rest of the list remains unaffected. So, you remove a piece without altering the rest of the contents.
The syntax for slicing a list is: List_name
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Python For Data Structures Algorithms And Interviews
This is the best Udemy course to learn Data Structure and Algorithms with Python on Udemy. This Python data structure course will teach you all the key data structures and algorithms you need for your day-to-day programming task and to crack coding interviews.
This course is created by none other than Jose Portilla, instructor of the Complete Python 3 Bootcamp course and it Talking about social proof, this course has on average 4.4 ratings from close to 7,892 ratings and more than 51,309 students have already enrolled in this course.
Here are the key things you will learn in this course:
- How to create a great resume
- How to build impressive LinkedIn and Github profile for recruiters
- All major Data Structures and Algorithms in Python like an array, lists, dictionaries
- Mock interviews to crack your next coding interview.
Overall a great Python course that systematizes your algorithm & data structure knowledge as well as gives you great exercises to test your skills both soft and hard skills and helps you to get success in interviews.
What Is The Result Of 10+20+30 In Javascript
This interview question tests your knowledge of JavaScript data primitives, the data types that can be composed into different data structures in Python. In this case, its a mix between string and numbers data types. Knowing that the result will be 102030 rather than 60 means that you understand that when a string type is invoked with the + operator in JavaScript, the automatic behavior is to turn it into a concatenation operator.
Only by ensuring that everything that interacts with the + operator is a number or BigInt data type can you ensure that a desired behavior of addition happens.
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Can You Explain The Working Of A Selection Sort
Selection sort follows a simple process to sort a list of elements. To start, the list is divided into two parts. The part on the left is sorted and the part on the right is unsorted. Initially, the list is unsorted so only the first element is on the left.
We then scan the array and find the smallest element. That element is swapped with the first element and becomes part of the sorted array. We then repeat this process with the second element and so on. The following image depicts the process.
What Is The Eligibility For A Job Assistance Program
We want candidates should also put their effort into completing the course and participate in the Weekly online coding test. All the performant subscribers in the coding test will be eligible for Mock interviews as well as Job referral program.
The weekly coding test is on hackerrank platform with 2 problems and 90 min of time frame.
There is no limit on the number of weekly coding test subscribers who want to attend. Subscribers can attend these weekly coding tests at any time. So, It’s advisable they should start participating in the weekly coding test when they feel confident on a particular topic.
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Commonly Asked Data Structure Interview Questions
What is a Data Structure? A data structure is a way of organizing data so that the data can be used efficiently. Different kinds of data structures are suited to different kinds of applications, and some are highly specialized for specific tasks. For example, B-trees are particularly well-suited for the implementation of databases, while compiler implementations usually use hash tables to look up identifiers.
What are linear and non-linear data Structures?
- Linear: A data structure is said to be linear if its elements form a sequence or a linear list. Examples: Array. Linked List, Stacks and Queues
- Non-Linear: A data structure is said to be non-linear if the traversal of nodes is nonlinear in nature. Example: Graph and Trees.
What are the various operations that can be performed on different Data Structures?
- Insertion ? Add a new data item in the given collection of data items.
- Deletion ? Delete an existing data item from the given collection of data items.
- Traversal ? Access each data item exactly once so that it can be processed.
- Searching ? Find out the location of the data item if it exists in the given collection of data items.
- Sorting ? Arranging the data items in some order i.e. in ascending or descending order in case of numerical data and in dictionary order in case of alphanumeric data.
Applications of Stack:
What are Infix, prefix, Postfix notations?
A * / D
A B C + * D/
The Complete Data Structures And Algorithms Course In Python
This is one of the top courses to learn Data Structures and Algorithms Courses in Python in 2022 from Udemy. You will learn data structure and algorithms from scratch and it also comes with 100+ coding problems for interviews.
This 41-hour long course is one of the most comprehensive Python data structure courses. This course is created by Elshad Karimove and it will teach you how to implement and use data structure in Python.
Here are the main things you will learn in this Python Course:
Overall a great Python course to learn the pros and cons of different Python data structures, so you can choose the best data structure for your data and applications.
Here is the link to join this course The Complete Data Structures and Algorithms Course in Python
Thats all about some of the best online courses to learn Data Structure and Algorithms in Python in 2022. As I have said, the list contains both free and paid courses and you can choose the one you like. Whatever course you choose, be honest with that and do all the exercises they suggest.
If you like you can practice more by solving common Data Structure and algorithm problems from interviews as well. You can see this list of 50+ Data structures and Algorithm problems to start with.
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Important Python Data Structures Interview Questions And Answers
Python Data Structures is an important topic in every Python based Interviews hence it is absolutely necessary for a candidate to have complete understanding of the questions and answers that can be asked from this topic. In this article, I have gone through all the possible Python Data Structures questions based on my experience. Hopefully this will help you crack all kinds of Python based Interviews.
What Is The Process Behind Storing Variables In Memory
The simplest way to store anything in the computers memory is using a variable. A variable represents one piece of data, such as a character or a number. Variables make it easier to write programmes because you can refer to values by their names and write generic programs or functions that work with any value.
The way variables are stored depends on the programming language being used. Some programming languages require declaring variables and others dont. There are certain programming languages in which variables can only be of a certain type while others are more flexible.
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Sample Python Data Structure Interview Questions For Practice
Here, we glance over some additional Python data structure interview questions that you can prepare for your tech interview:
These top Python data structure interview questions will help you prepare for your software developer interview and ace it. After you’ve finished your preparation, you can take some mock interviews for self-evaluation.
Are you preparing for a tech interview? Check out our Technical Interview Prep Checklist to plan your prep.
Leetcode In Python: 50 Algorithms Coding Interview Questions
This is one of the unique courses to learn Python data structure and algorithms in 2022 on Udemy. Its particularly useful for Python programmers who are preparing for coding interviews and wants to practice data structure and algorithms problems in Python.
This course actually takes LeetCode problems and provides the solution in Python and explains to them which kind of makes it useful as you learn about problem-solving, data structures, and algorithms for technical interviews at companies like Google and Amazon.As the title suggests it provides a solution of 50 hand-picked leetcode problems which include data structure string, array, list, dictionaries, trees, hash tables, graph, stack, queue, etc.
You will also learn a lot of useful algorithms like sliding windows, backtracking, dynamic programming, and learn some useful problem-solving tips to solve coding problems in real interviews.
On the cons side, the course has some sound issues but the content and style compensate for that. I really like the idea of two videos explanation and implementation, which make learning easy and fruitful. Talking about social proof, the course has an average 4.5 rating which is impressive.
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These Are The Best Online Courses To Learn Data Structure And Algorithms In Python Algorithm Code Examples Are Given In The Python Programming Language
Hello Python Programmers, if you want to learn Data structure and Algorithms in 2022 and looking for the best online courses where you can find common data structure examples in Python then you have come to the right place.
In the past, I have shared a lot of useful resources like best data structure courses, books, and tutorials to learn Data Structure and Algorithms for programmers.
I have also shared a lot of Algorithmic interview questions and their solutions in Java, but I have been constantly getting queries about good courses to learn Data Structure and Algorithms in Python.
Even though the topics are completely independent of the programming language, Python developers definitely like the courses and books which teach Data Structure and Algorithms in Python.
This time, I have focused more on coverage of essential data structure in a fun and interesting way, rather than picking the course which covers a huge number of data structure and algorithms but didnt do justice with that.
Another reason I have included more than a few courses is because not everybody connects to the instructor I like. Everybody is different and they should only join the course where they can connect to the instructor, I mean they like his voice, the style of explanation, and the content.
What Is A Data Structure
Simply put, a data structure is a container that stores data in a specific layout. This layout allows a data structure to be efficient in some operations and inefficient in others. Your goal is to understand data structures so that you can pick the data structure thats most optimal for the problem at hand.
Why do we need Data Structures?
As data structures are used to store data in an organized form, and since data is the most crucial entity in computer science, the true worth of data structures is clear.
No matter what problem are you solving, in one way or another you have to deal with data whether its an employees salary, stock prices, a grocery list, or even a simple telephone directory.
Based on different scenarios, data needs to be stored in a specific format. We have a handful of data structures that cover our need to store data in different formats.
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What Are The Different Types Of Data Structures
The different types of data structures are:
- Arrays: A collection of data values stored sequentially
- Stacks: Last-in-first-out data structures where the element placed last is accessed first.
- Queues: A first-in-first-out data structure.
- Linked lists: A collection of data values stored in a linear order and connected to each other
- Graphs: A data structure in which data values are placed in nodes connected by edges
- Trees: Similar to a linked list, but with data values linked in a hierarchical fashion
- Heaps: A binary tree data structure wherein parent data values can be compared to child data values
- Hash table: A table where each value is assigned a key and then stored, making accessing individual values easy.
Understanding Data Structure And Algorithms Syllabus For Coding Interview
After preparing the mind, now our first goal would be to prepare a list of essential topics important in data structure and algo. We can especially focus on real-life applications to understand the use case of algorithms.
Algorithmic and Mathematical Thinking
A blog to explore: How to develop algorithmic thinking?
Fundamentals of Programming
Data Types, Variables, Operators, Expressions, Control statements, Loops, Functions, Pointer and Reference, Arrays, Strings, Memory Management, Fundamental of OOPS, etc.
Fundamentals of Algorithms
- Algorithm Introduction: Properties and real-life applications of algorithms
- Complexity Analysis: Input size, Rate of growth, Time complexity, Big-O notations, Worst-case analysis, Best-case analysis, Average-case analysis, Space complexity analysis, etc.
- Sorting: Bubble sort, Selection sort, Insertion sort, Merge sort, Quicksort, Heap sort, Counting sort, Radix sort, Properties and comparisons of sorting algorithms, etc.
- Searching: Binary search, Exponential search, Interpolation search, etc.
- Hashing: Direct address table, The idea of a hash table, Properties and design of a good hash function, Basic operations , Patterns of problem-solving using a hash table, Collision resolution techniques like chaining and open addressing, etc.
Linear Data Structures
A blog to explore: Introduction to Data Structures
Properties, Structure, Implementation, Basic operations, Patterns of iterative and recursive problem-solving and Real-life applications
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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.
Access Common String Groups With String Constants
Its trivia time! Is ‘A’ > ‘a’ true or false?
Its false, because the ASCII code for A is 65, but a is 97, and 65 is not greater than 97.
Why does the answer matter? Because if you want to check if a character is part of the English alphabet, one popular way is to see if its between A and z .
Checking the ASCII code works but is clumsy and easy to mess up in coding interviews, especially if you cant remember whether lowercase or uppercase ASCII characters come first. Its much easier to use the constants defined as part of the string module.
You can see one in use in is_upper, which returns whether all characters in a string are uppercase letters:
> > > importstring> > > defis_upper:... forletterinword:... ifletternotinstring.ascii_uppercase:... returnFalse... returnTrue...> > > is_upperFalse> > > is_upperTrue
is_upper iterates over the letters in word, and checks if the letters are part of string.ascii_uppercase. If you print out string.ascii_uppercase youll see that its just a lowly string. The value is set to the literal ‘ABCDEFGHIJKLMNOPQRSTUVWXYZ’.
All string constants are just strings of frequently referenced string values. They include the following:
- string.ascii_letters
These are easier to use and, even more importantly, easier to read.
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