50 Frequently Asked Python Interview Questions and Answers
At present, Python is one of the most advanced and demanding programming languages that let anyone work more quickly and efficiently and helps to integrate the system more effectively. The language formulates on an object-oriented approach, that helps programmers to write readable and logical code for any scaled (large or small) projects. A developer’s caliber will be evaluated by his/her programming skills, analytical ability, problem-solving capability in the shortest possible time, and his vast knowledge on the tools and language that he will be using to do so. To assist you with your upcoming interview, we have short-listed the top 50 Python Interview Questions and Answers.
Python Interview Questions and Answers
With this basic information on Python, let us move into the most popular questions that you should expect to be asked during your interview.
- Firstly, you will be assessed on your basic knowledge of Python, which may include popular commands, key features, memory management, etc.
- Secondly, you will be judged on your knowledge of object-oriented programming and Python libraries.
- Finally, your problem-solving skills, using various algorithms will be examined.
Here, we have outlined a few popular python interview questions that will brush up your knowledge on Python, and get you ready for the interview.
Q-1: What is Python?
The first entry in this list of Python interview questions is one of the most basic ones. However, the majority of interviewers never skip this basic question. Python is one of the most progressive, elevated levels, broadly useful, powerful programming dialects with objects, modules, strings, special cases, and programmed memory management.
It is adaptable, simple to utilize, and quick to create. Moreover, it has an open-source and vibrant community, and one can get all the libraries that he/she can imagine. However, it has some limitations with speed, few problems with threading, and the harshest part that it is not native to a mobile environment.
Q-2: Explain Some Key Features of Python
Countless programming languages are famous because of their specialties, but what makes a programming language unique is its key features. The key features that you should remember are as follows:
- Easy to Read and Code: Python is very easy to code due to its easy syntaxes; as a result, it takes a few hours to acquire them. Moreover, code readability is very simple, and one can simply see the code and understand the functionality of the code.
- Interpreted Language: Python is an interpreted language like PHP and Ruby, which means it does not need to compile before it runs.
- Dynamically Typed: Python is dynamically typed, which means while writing code, you don’t need to declare or set a type to a variable while assigning a value or task to it.
- Large Standard Library: One of the best features of Python that saves a lot of time while writing code is its available standard library as one does not have to write a code for every single thing.
- High Level: Python is a high-level language; as a result, programmers can code without worrying about the system architecture, nor they have to think about the memory, which makes Python a programmer-friendly language.
- Object-Oriented Programming: Python supports both procedure-oriented and object-oriented programming. In OOP, it permits the meaning of classes alongside synthesis and legacy and doesn’t have any specifiers (open, private).In OOP, it allows the meaning of classes alongside creation and legacy and doesn’t have any specifiers (open, private).
Q-3: How is Memory Managed in Python?
Memory management in Python, for the most part, includes a private pile space, where every one of the information structures and articles is found. Python additionally has an inbuilt city worker that will reuse the unused memory and make it accessible to the load space.
Q-4: What is the PYTHONPATH environment variable?
PYTHONPATH is an environment variable that has a string value, which is added in Python’s system directory list as it has a set of directories. PYTHONPATH is generally used when we have not made any installable Python package, but we want to import some code that we have written in a program.
Q-5: What is the Difference Between List and Tuple in Python?
The most applicable response to this python programming interview question would be that List and Tuple behave almost the same way, and any item stored in a List or Tuple can be accessed by its index. Still, two major differences between them are that List is mutable, but Tuple is immutable, which means, List can be modified, but Tuple cannot be modified. Besides, Lists are slower than Tuples.
Q-6: How is Python an Interpreted Language?
An interpreted language is a language that is read in its raw form, and the statements are executed without being first compiled. Python is an interpreted language as it runs directly from the source code. The source code written by the programmer is first converted into an intermediate language and then to a machine language that has to be executed.
Q-7: What are the tools that help to find Bugs or Perform Static Analysis?
Pychecker and Pylint are the static analysis tools that help to find bugs in Python. Pychecker is an open-source device that gets bugs from the source code and shows cautioning about the style and unpredictability of the code.
Pylint has a special purpose, and it controls warning and errors. It searches for programming blunder and keeps up the programming standard. It checks the length of each programming line and whether the names of the variable are like the undertaking style.
Q-8: What is PEP 8?
PEP represents the Python Enhancement Proposal. It is a set of rules to allow maximum readability of Python code in terms of formatting. The document describes new features for Python, which includes design and style, suggested by the community.
Q-9: What is the Difference Between remove() function and del statement?
The remove() function deletes the matching element/object, whereas del removes the element at a specific index. This is one of the basic Python programming interview questions that interviewers never want to miss out on.
Record is the main capacity that searches an article (not record). If we need to erase a particular item in the rundown, we can utilize the evacuate strategy. If we need to erase the article at a particular area (a record) on the rundown, we can either utilize del or pop.
Q-10: What is the shuffle() Method in Python?
The shuffle() method, for the most part, takes a succession (rundown, string, or tuple) from the program and rearranges the request for the things. Be that as it may, this technique changes just the first rundown/tuple/string, it doesn’t restore another rundown/tuple/string. This is a significant python inquiry question.
Syntax
random.shuffle(sequence, function)
Parameter Values
| Parameter | Description |
| sequence | It is Required. A grouping. It very well may be a rundown, a tuple, or a string. |
| function | It is Optional. The name of a function that returns a number between 0.0 and 1.0. If it is not specified, the function random() will be used |
Q-11: Why do we Use join() Function in Python?
This is another asked python programming interview question among the important python interview questions. The join() work is a string method that profits a string linked with the components of an iterable. This technique gives an adaptable method to connect string. It links every component of an iterable, (for example, rundown, string, and tuple) to the string and afterward restores the connection string.
The syntax of join() is: string.join(iterable)
Join() Parameters: Join() method takes an iterable – objects capable of returning its members one at a time.
Return Value: This technique restores a string connected with the components of iterable.
Q-12: What is lstrip() Function in Python?
The lstrip() is the strategy that profits a duplicate of the string with driving characters expelled (because of the string contention passed). It is a common Python coding interview question often asked. It expels characters from the left, dependent on the contention (a string determining the arrangement of characters to be evacuated).
The syntax of lstrip() is: string.lstrip([chars])
lstrip() Parameters: chars
Return Value: lstrip() will return a copy of the string with leading characters stripped. Every one of the mixes of characters in the singes contention is expelled from the left of the string until the primary confound.
Q-13: What is swapcase() Function in Python?
The string swapcase() strategy changes over every single capitalized character to lowercase and do the other way around of the given string, and returns it.
Syntax: string_name.swapcase()
Here the string name is the string whose cases are to be swapped.
Parameter: The swapcase() technique, by and large, doesn’t take any parameter.
Return value: The swapcase() technique will restore a string with every one of the cases changed. That is to say, swapcase() technique restores the string where every single capitalized character is changed over to lowercase, and lowercase characters are changed over to capitalized.
Q-14: Can Python be used for web client and web server side programming?
This question is discussed in Python interview questions and answers frequently by the interviewers. Python can be utilized to fabricate web server-side programming and applications. Be that as it may, the greater part of the Python engineers composes their web applications utilizing a blend of Python and JavaScript. While Python is executed on the server-side, JavaScript is downloaded to the customer and run by the internet browser.
Python is a high-level language with good package support and several matured Web application frameworks. Writing a Web application in Python is likely to produce results very rapidly given the number of supporting libraries, examples, and code snippets available to web developers.
Q-15: Mention the benefits of using Python over Javascript
Python is contrasted with other deciphered dialects, for example, Java, JavaScript, Perl, Tcl, or Smalltalk various occasions. It is often asked in Python programming interview question, why it is most preferable.
These comparisons are mainly concentrated on language issues only. In the handy world, the decision of a programming language is regularly directed by other certifiable limitations, for example, cost, accessibility, preparing, and earlier speculation, or even enthusiastic connection. Since these angles are exceptionally factor, it normally appears to be an exercise in futility to think of them as much for this examination.
Some of its benefits are-
- Extensive Support Libraries
- Integration Feature
- Improved Programmer’s Productivity
- Productivity of applications
- excellent support community
Q-16: Does Python allow you to program in a structured style?
One of the key Python interview questions includes if we can program in a structured style. As Python is a high-level programming language, it supports both objects as well as structured oriented language.
A structured style is used to reduce faults and misinterpretation in a huge program by breaking it down into smaller modules where each module uses structured codes, thus making it a more well-organized program.
These include, if clauses, for/while loops, assignment statements, sequences (such as strings, lists, and tuples), stacks and queues, etc.
Q-17: What is PIP software in the Python world?
Sometimes in Python interview questions, we are asked about PIP software. PIP is nothing but a package manager (containing all the records required for a module) or a standard package management system that is used to install as well as manage software packages written in Python.
This permits us to use other libraries that are not available in the standard library. One of the greatest advantages of using PIP is, how easily one can use a command-line-interface, thus making life easier in installing Python software packages. Other features of PIP also include the way we can manage the full lists of packages and the numbers, respectively, through a “requirements” file.
Q-18: What should be the typical build environment for Python-based application development?
Python code needs to be written, implemented, and verified to build applications. The two most basic things required to develop Python-based applications are text editor and a terminal.
The text editor allows us to write the code, whereas the runtime environment implementation such as CPython or PyPy delivers the technique for executing the code. In this way, it tests the code and checks if it works what we want by either manually or by unit and functional tests. Text editors include Sublime, Notepad++, or even a complete IDE such as PyCharm.
Q-19: What tools can be used to unit test a Python code?
Python basic interview questions include the tools that can be used to test the Python code. It is very important to test the code that has been written as it checks if it runs the way we want it to. It is a very tedious job to check the entire code manually, and also increases the chance of error.
There are mainly four tools used to test the Python code. They are Unittest (a Python module for creating tests), Nose (a test runner for your tests), Coverage (measuring the code coverage), and Mock (faking objects for unit tests).
Q-20: How does For loop and While loop differ in Python?
Often in our Python coding interviews, we are asked questions regarding loops. A loop can perform a block of code numerous times until a particular condition is met. There are mainly 2 loops, for loop and while loop.
A for loop is used when we know how many times the code should run. That particular piece of code will iterate “n” number of times.
Whereas, a while loop is used in code to repeat some statements, and it runs until a condition is false. It is almost similar to “if statement” except that it does not run only once.
Q-21: How are data types defined in Python?
The coverage of the best Python interview questions would also include this particular question. Usually, we know a data type describes the format of the data that is to be input by the user, so it can be used properly. In Python, a variable does not need to be declared by mentioning its data type(also known as dynamic typing) it determines the type of a literal straight from the syntax at runtime.
Some important data types in Python are Booleans, Numbers, Strings, Bytes, Lists, Tuples, Sets, and Dictionaries. Integer data types hold 4 bytes, and Decimal data types hold 4 bytes.
Q-22: How do you make use of Arrays in Python?
Python programming interview questions incorporate the utilization of arrays. Arrays are special variables and are used to store multiple values in one single variable, at continuous memory locations, thus making it easier to calculate the position of each element just by adding an offset to a base value. Not only this, but they can also store elements of the different data types.
To create array we write : array(data_type, value_list). To add elements in the array, we write: insert(). To remove array, we write: remove(). We use slice operation to print a particular scope of components from the exhibit.
Q-23: Given that Python is best suited for the server-side application, how do you implement JSON?
We are often asked about JSON in our Python coding interview questions. JSON is the short type of JavaScript Object Notation. JSON is a powerful way to allow transmission between client and server, and an easy to read, adjustable text format used to store and communicate information to other products.
To implement JSON, python has a JSON module that helps convert data structures to JSON strings. We first need to import the function to import the JSON module by writing: import JSON. At that point, the JSON module is utilized to change over the python lexicon into a JSON string that can be composed into a record.
Q-24: What is the best way to parse strings and find patterns in Python?
Often in Python interview questions and answers, we are asked the way to parse strings. Parsing a string is to analyze a particular string or text and convert that data into a more usable format.
We can parse strings in a standard format by using an existing package to read the data, or we can parse texts using string methods by using the common string operations and extract data from a string, or we can also parse in a complex format using regular expressions. re.search() is commonly used to search for patterns in a text in Python.
Q-25: Which databases are supported by Python?
Several times we are asked this in Python interview questions, and to answer this, we should explain what a database is. A database is a structured set of data that is held in a computer and is accessible in numerous ways. The two most common databases supported by Python are PostgreSQL and MySQL.
The feature set, active development, and stability of PostgreSQL are the main reason why we can find abundant live applications on the Web today. MySQL, the most popular open-source database management system, is a relational database that stores data in distinct tables instead of putting all the data in one space.
Q-26: How can you create a GUI based application in Python for client-side functionality?
This Python interview question asks for making a user-friendly application that is easy for the client to use. First, the purpose of your client needs to be considered – if your client needs data on electricity consumption, your GUI must be able to view a bar chart, for example. Therefore, an appropriate GUI toolkit must be used.
Secondly, an appropriate GUI package must be selected. For instance, Kivy can be used for mobile applications. Thirdly, write the required codes in order to make a colorful application, having a table of menus to select from, user account to login, and other features summarized in the picture below.
Q-27: What is a generator in Python?
This is an often asked Python coding interview question. Generators return a group of iteration-values in a for a loop upon reaching the yield statement. The new values are then substituted within a function, and the generator can run over and over again.
Q-28: What is slicing in Python?
This is another most recent Python programming interview question. slice( ) creates a slice object. The syntax of the slice is:
slice(stop)
slice(start, stop, step)
Sequences that can be cut up incorporate range, tuple, string, bytes, and rundown.
Q-29: What is a dictionary in Python?
This is a Python interview question on different functions of the Python library. Dictionary is a group of data values that are not ordered. The dictionary stores a key-value pair rather than one value. Any data type can be declared for the value, and the value can also be repeated, but care must be taken to keep the key unique.
Another method of forming a dictionary is by using dict( ). The following diagram shows that value ‘coffee’ is repeated for different keys, ‘drinks’ and ‘cocoa.’
Q-30: What is Pass in Python?
This is a basic Python interview question. Pass is a null statement. Unlike a comment which is not run, the pass is run by the compiler. Pass is a placeholder that creates an empty body so that a loop or function can be written later on.
Q-31: What is a negative index in Python?
This is a Python interview question that asks to apply indices suitably. A negative index assigns a value of -1 to the last element in a list, array, or other container classes, a value of -2 to the second last element, and so on. This is a turn around requesting a framework.
Q-32: What is pickling and unpickling in Python?
This is a habitually asked Python coding interview question. Pickling is the method of transforming an object hierarchy into a byte stream. Unpickling transforms byte stream back to an object hierarchy.
Q-33: Which programming language is a good choice between Java and Python?
The Python programming interview question asks for a comparison between the two. Variable types do not have to be declared because the compiler can detect them. The syntax is similar to pseudocoding, whereas Java has a too rigid syntax. Both Java and Python have cross-platform, backend frameworks, machine learning libraries, and game development engines. The only advantage Java has over Python is speed; however, the advantage of easy learning of Python far outweighs all the advantages of Java, so Python is a good choice.
Q-34: What are the differences between Python2.x and Python3.x?
The Python basic interview question asks for the updates that Python 3.x has, which Python 2.x does not have. Python 3.x has addressed the flaws of the previous Python 2.x. In Python 3.x, print( ) is a function, whereas in Python 2.x, print{ } is a statement. Unicode is the implicit string type by default in Python 3.x, and ASCII string is used in Python 2.x. The actual float value of division is returned for the input of integer or float in Python 3.x, but a rounded up division integer value in Python 2.x. xrange function in Python 2.x is replaced by range( ) in Python 3.x.
Q-35: What is the use of Assertions in Python?
This is the highest asked Python interview question. An assertion checks if the returned boolean value is 0 or 1. For 1, the next code line is executed. For 0, an error message is shown.
Q-36: What is the distance between ‘match’ and ‘search’ in Python?
This Python programming question asks for the functionality of match and searches that is part of the re-module in Python. Match and search are functions that try to find a smaller string within a larger string. Either the matched object is returned, or nothing is returned. However, the two functions are very different from one another. Match function looks for the object in the first line, whereas the search function looks for the entire string, even if the matched object gets repeated in several lines.
Q-37: What is the difference between a shallow copy and a deep copy?
This Python coding interview question asks to differentiate between deep copy and shallow copy, available under copy module in Python. A deep copy or a profound duplicate duplicates an exhibit, list, and so forth in a recursive way. A collection of objects is created before cloning elements of the original collection. Any element’s value altered in the new set does not alter the old set.
Shallow copy produces a reference to the original collection, so changes to one collection causes the other to change. In table 1, the third element remains unchanged for deep copying, whereas in table 2, both the collection’s third object changes due to shallow copying.
Table 1
| List1 | List2(Is A Deep Copy Of List1) | Modified List2 | List1(Unchanged) |
| Mina | Mina | Mina | Mina |
| Lina | Lina | Lina | Lina |
| Rina | Rina | Lina | Rina |
Table 2
| List1 | List2(Is A Shallow Copy Of List1) | Modified List2 | List1(Changed) |
| Mina | Mina | Mina | Lina |
| Lina | Lina | Lina | Lina |
| Rina | Rina | Lina | Lina |
Q-38: What are help( ) and dir( ) in Python?
This Python basic interview question asks to explain help( ) and dir( ) in a manner that helps to understand that the two functions are distinct and not the same. help( ) is used to get documentation details on any Python object, such as module, class, etc. dir( ) returns qualities and techniques for a Python object. dir( ) is also used to find coding errors.
The following shows a code of dir( ) along with output.
Q-39:What is the difference between locals( ) and globals()?
This is a Python coding interview question that asks to separate the concept of the locals( ) and globals( ). Local variables are declared inside a function body, so when the same variable’s name is written inside another function, the variable has two different values. Global variables are written outside all functions so that when the variable name is written inside a function, the function recognizes the variable.
If a local variable is not initialized, a garbage value is stored. If a global variable is not initialized, zero is stored. A local variable is created when a function starts and lost when the function ends, whereas a global variable is created when the program starts and lost when the program ends.
Only for local variables, parameter passing is essential. A local variable is accessed inside a function with help( ), which is not required in the case of the global variable. A local variable is stored on a stack, and a global variable is stored on a fixed location.
Q-40: What are Python decorators?
This Python coding interview question asks for how to create a function within a function. A decorator is a Python function that modifies the behavior of a higher-order function or class without changing the function or class explicitly. In other words, new functionality is provided to the function or class.
One function is passed into another function as an argument. Accordingly, wrapper work is made. An example of three functions, one wrapped in the other, is shown below.
Q-41: What is the purpose of the _init_() function in Python?
A very familiar python interview question is the purpose of _int_() function in python. In python _int_() is such kind of function that that is basically used as a constructor. This one is a reserved method for python. As this is a constructor for an object-oriented language, so when an object is created for a class, it allows that class to initialize class along with its attributes.
Not necessarily every time we have to use it at the initial position of a class. We can use it wherever the position we want for it, but the traditional way of using it is in the starting position.
Q-42: Mention the significance of the ‘self’ parameter in an object method?
A very basic python coding interview question is the significance of the ‘self’ parameter in an object method. Well, ‘self’ itself is an object reference, so object and ‘self’ are the same.
‘self’ always points to the object that has been created from that particular class. By the object self, we can get access to a particular class’s method. In python, ‘self’ is a customary name. We can generally use anything else in its place.
Q-43: How does Lambda function differ from a normal function in Python?
A very well known python basic interview question is how does lambda function differ from normal python function. In python language, a lambda function is used as data as the meaning of lambda is the function that is used as data.
There is the main difference between lambda function and a normal function in python, which is a lambda function’s body is made of a single expression. And also, the outcome of this is returned from the function that has been created. Lambda expression creates a function object and also combined a function with a name that doesn’t have any value.
Q-44: How is Exception Handling done in Python?
One very important python basic interview question is how exception handling is done on python. The event exception happens during the execution time of a program when something unusual or an error occurs, and it can also be handled during that time.
Handling an exception means to act against the error or exception that has been occurred. In python, ‘try’ and ‘except’ are two keywords that are used to catch the unusual error whine running any program.
Q-45: What is the starting point of Python code execution?
A must ask python programming interview question is, which would be the starting point of python code execution. For any kind of function, no matter in which language ‘main’ is the entry point of a program to be executed.
In python, the compiler or the interpreter executes the source file in an ordered way, and it doesn’t read any method which is not directly connected to the program. We can likewise execute the record as content in python.
Q-46: Name some of the important modules that are available in Python.
One of the very important python interview questions is the important available modules in python. There are a few modules for python. These modules are only python library.
Some very popular python modules are – Pandas, NumPy, Scikit-Learn, PyTorch, MatPlotLib, SciPy, etc.
Q-47: What is namespace in Python?
A very basic python interview question what namespace is. The namespace is something that ensures the uniqueness of any object from another object as well as gives us additional information about that name like the names type, variable, function, etc.
A namespace is used in code for preventing the clash inside a code, specifically when we use multiple libraries and also to design the code in an organized way. In python, an object can be a method or variable, so by using namespace; python keeps track of that object so that the interpreter can identify it easily.
Q-48: How do you launch sub-processes within the main process of a Python application?
An extremely commonplace python interview question is the means by which to dispatch sub-forms inside the primary procedure in python application. Propelling a sub-process is significant in python since it permits running new applications or new code utilizing python code by making another procedure.
In python subprocess module grants you to bring forth new procedures that are associated with inputs, yields, mistake pipes, and that is the manner by which to achieve their arrival code. This module is likewise permitted to supplant a few more established modules.
Q-49: Do we need to call the explicit methods to destroy the memory allocated in Python?
A pretty famous python coding interview question is then whether we need to call an explicit method to destroy the memory that has already been allocated in python. Well, python doesn’t require to call an explicit method to destroy the allocated memory.
In python, there are a total of three generations for garbage collection for each time it endures a garbage collection session in it. The user will not need to bother about memory management as python itself removes the unnecessary objects from its memory.
Q-50: Does the same Python code work on multiple platforms without any changes?
A must ask python coding interview question is to know if python can be run in multiple platforms without changing. As Python is a very convenient language, it can be run in multiple platforms without changes or maybe with very little change.
Python is called a cross-platform language. The structure of this language allows it to run any other operating system like windows Linux etc. all it required is to have a python interpreter to interpret the python code for the particular platform we want it to run on.
Finally
Python is now one of the most demanding languages,, and therefore, we have gathered all the important and most asked Python interview questions that will help you to brush up all the crucial topics in depth. But in order to have a greater hand in your interview, you should try to have a personal tutelage that will make you practically skilled as well.
You also have to keep in mind that any tricky and complicated Python interview questions can be asked to examine your knowledge of Python. So, you always have to keep your skills up-to-date and furnish them. You have to learn and practice Python scrupulously in order to ace that interview.
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