Python Interview Questions and Answers for Beginners 

Here is the set of questions which helps you to revise the basic concepts of python to crack the interview.

1. How many modes are there in Python?

      Python has two basic modes: script and interactive.

2. What is a Script mode?

     The normal mode is the script mode where the scripted and finished .py files are run in the Python interpreter.

3. What is the interactive mode?

 Interactive mode is a command line shell which gives immediate feedback for each statement, while running previously fed       statements in active memory.

4. What is the use of Pycharm?

PyCharm is an Integrated Development Environment (IDE) used in computer programming, specifically for the Python language. It provides code analysis, a graphical debugger, an integrated unit tester, integration with version control systems (VCSes), and supports web development with Django.

5. Why is Python so powerful?

Python is easy to use, powerful, and versatile, making it a great choice for beginners and experts alike. Python’s readability makes it a great first programming language — it allows you to think like a programmer and not waste time understanding the mysterious syntax that other programming languages can require.

6. What is a file in Python?

A file is some information or data which stays in the computer storage devices. Python gives you easy ways to manipulate these files. Generally we divide files in two categories, text file and binary file. Text files are simple text where as the binary files contain binary data which is only readable by computer.

7.  What is the input function in Python?

A) Input can come in various ways, for example from a database, another computer, mouse clicks and movements or from the internet. Yet, in most cases the input stems from the keyboard. For this purpose, Python provides the function input(). input has an optional parameter, which is the prompt string.

8. Is Python a compiled or interpreted language?

A) Python will fall under byte code interpreted. . py source code is first compiled to byte code as .pyc. This byte code can be interpreted (official CPython), or JIT compiled (PyPy). Python source code (.py) can be compiled to different byte code also like IronPython (.Net) or Jython (JVM).

Python Interview Questions and Answers for Intermediates

Here are set of python interview questions with answers for intermediates to crack the interview successfully. Check out the questions and answer them to explore the knowledge.

1) What is the use of MAP in Python?

A) The map function is the simplest one among Python built-ins used for functional programming. These tools apply functions to sequences and other iterables. The filter filters out items based on a test function which is a filter and apply functions to pairs of item and running result which is reduce.

2) What is a sequence in Python?

A) In Python, sequence is the generic term for an ordered set. There are several types of sequences in Python, the following three are the most important. Lists are the most versatile sequence type. The elements of a list can be any object, and lists are mutable – they can be changed.

3) What does ORD () do in Python?

A) ord(c) in Python Given a string of length one, return an integer representing the Unicode code point of the character when the argument is a unicode object, or the value of the byte when the argument is an 8-bit string.

For example, ord(‘a’) returns the integer 97

4) What is a tuple in Python?

A) A tuple is a sequence of immutable Python objects. Tuples are sequences, just like lists. The differences between tuples and lists are, the tuples cannot be changed unlike lists.

5) What is the difference between a list and a tuple?

A) List is mutable and tuples is immutable. The main difference between mutable and immutable is memory usage when you are trying to append an item. When you create a variable, some fixed memory is assigned to the variable. If it is a list, more memory is assigned than actually used.

6) What is a cast in Python?

A) Casting is when you convert a variable value from one type to another. This is, in Python, done with functions such as int() or float() or str() . A very common pattern is that you convert a number, currently as a string into a proper number.

7) Can you explain this why are we getting an error here?

>>>sqrt(3)

Traceback (most recent call last):

File “<pyshell#17>”, line 1, in <module>

sqrt(3)

NameError: name ‘sqrt’ is not defined

A) In the above code, sqrt() function is available in the “math” module and that we have to load import the “math” module before we can call the “sqrt()” functions.

8) What is a module in python?

A) In Python, module is a package that contains a set of functions to do a specific task. For example “math” module provides some math related functions like sqrt().

Python Interview Questions and Answers for Experienced

If you are experienced then surely you have worked on projects and this is the only tool which can drive the interview on your side. Let’s explore the most important python interview questions for  experienced.

1) What is string replication operator in Python?

A) * is the string replication operator, repeating a single string however many times you would like through the integer you provide.

Example: Let’s print out “Python” 5 times without typing out “Python” 5 times with the * operator:

print(“Python” * 5)

Output: PythonPythonPythonPythonPython

2) What is the output of this below query?

ss = “Python Programming!”

print(ss[5])

A) Output of the above code is: n

3) What is GIL in Python?

A) In Python, GIL (Global Interpreter Lock) is a mutex that protects access to Python objects, preventing multiple threads from executing Python bytecodes at once.

4) What is meant by mutex in Python?

A) In Python programming, a mutex (mutual exclusion object) is a program object that is created so that multiple program thread can take turns sharing the same resource, such as access to a file.

5) Is Python supports Multithreading?

A) Yes Python supports multithreading concept with the help of Global Interpreter Lock (GIL).

6) Explain the use of Ternary operator in Python?

A) In Python, Ternary operator added in the version 2.5. It is used as a conditional statement, it consists of the true or false values. Ternary operator evaluates the statement and stores true or false values.

Python Ternary Operator Syntax :

[on_true] if [expression] else [on_false]

Python Ternary Operator Example:

a, b = 22, 35

# Checking the minimum number and storing in mini

mini = a if a < b else b

print(mini)

Output: 22

7) What is memory management in Python?

A) Memory management in Python involves a private heap containing all Python objects and data structures. The management of this private heap is ensured internally by the Python memory manager.

8) What are the components of Python Memory Manager?

A) The Python memory manager has different components which deal with various dynamic storage management aspects, like sharing, segmentation, preallocation or caching.

Top Python interview questions and answers for experienced

If you are experienced then surely you have worked on projects and this is the only tool which can drive the interview on your side. Let’s explore the most important python interview questions for experienced.

1. What is a closure in Python?

 A closure in Python is said to occur when a nested function references a value in its enclosing scope. The whole point here is that it remembers the value.

>>> def A(x):

def B():

print(x)

return B

>>> A(7)()

Output  7

2. What will the following code output?

>>> a=1

>>> a,b=a+1,a+1

>>> a,b

The output is (2, 2). This code increments the value of a by 1 and assigns it to both a and b. This is because this is a simultaneous declaration. The following code gives us the same:

>>> a=1

>>> b,a=a+1,a+1

>>> a,b

(2, 2)

3. What is the Dogpile effect?

 In case the cache expires, what happens when a client hits a website with multiple requests is what we call the dogpile effect. To avoid this, we can use a semaphore lock. When the value expires, the first process acquires the lock and then starts to generate the new value.

4. Explain garbage collection with Python.

 The following points are worth nothing for the garbage collector with CPython-

Python maintains a count of how many references there are to each object in memory

When a reference count drops to zero, it means the object is dead and Python can free the memory it allocated to that object

The garbage collector looks for reference cycles and cleans them up

Python uses heuristics to speed up garbage collection

Recently created objects might as well be dead

The garbage collector assigns generations to each object as it is created

It deals with the younger generations first.

5. Differentiate between split(), sub(), and subn() methods of the remodule.

The re module is what we have for processing regular expressions with Python. Let’s talk about the three methods we mentioned-

split()- This makes use of a regex pattern to split a string into a list

sub()- This looks for all substrings where the regex pattern matches, and replaces them with a different string

subn()- Like sub(), this returns the new string and the number of replacements made

Python interview questions and answers for 2 years experience

 If you are experienced then surely you have worked on projects and this is the only tool which can drive the interview on your side. Let’s explore the most important python interview questions for 2 years experienced.

1. What is the difference between interpreted and compiled languages?

A) Java (interpreted) and C (or C++) (compiled) might have been a better example. Basically, compiled code can be executed directly by the computer’s CPU. The code of interpreted languages however must be translated at run-time from any format to CPU machine instructions. This translation is done by an interpreter.

2) Is Python Interpreted or Compiled?

A) py source code is first compiled to byte code as .pyc. This byte code can be interpreted (official CPython), or JIT compiled (PyPy). Python source code (.py) can be compiled to different byte code also like IronPython (.Net) or Jython (JVM). There are multiple implementations of Python language.

3) What is an interpreter for Python?

A) The interpreter operates somewhat like the Unix shell: when called with standard input connected to a tty device, it reads and executes commands interactively; when called with a file name argument or with a file as standard input, it reads and executes a script from that file.

4) Is Python a procedural language?

A) Python is a multi-paradigm; you can write programs or libraries that are largely procedural, object-oriented, or functional.

5) What is a list in Python?

A) A list is a data structure in Python that is a mutable, or changeable, ordered sequence of elements. Each element or value that is inside of a list is called an item.

Interview questions and answers for 5 years experience

If you are experienced then surely you have worked on projects and this is the only tool which can drive the interview on your side. Let’s explore the most important python interview questions for 5 years experienced.

1. What is the function to randomize the items of a list in-place?

Ans. Python has a built-in module called as <random>. It exports a public method <shuffle(<list>)> which can randomize any input sequence.

import random

list = [2, 18, 8, 4]

print "Prior Shuffling - 0", list

random.shuffle(list)

print "After Shuffling - 1", list

random.shuffle(list)

print "After Shuffling - 2", list

2. What is the best way to split a string in Python?

Ans. We can use Python <split()> function to break a string into substrings based on the defined separator. It returns the list of all words present in the input string.

test = "I am learning Python."

print test.split(" ")

Program Output.

Python 2.7.10 (default, Jul 14 2015, 19:46:27)

[GCC 4.8.2] on linux

['I', 'am', 'learning', 'Python.']

3. What is the right way to transform a Python string into a list?

Ans. In Python, strings are just like lists. And it is easy to convert a string into the list. Simply by passing the string as an argument to the list would result in a string-to-list conversion.

list("I am learning Python.")

Program Output.

Python 2.7.10 (default, Jul 14 2015, 19:46:27)

[GCC 4.8.2] on linux

=> ['I', ' ', 'a', 'm', ' ', 'l', 'e', 'a', 'r', 'n', 'i', 'n', 'g', ' ', 'P', 'y', 't', 'h', 'o', 'n', '.']

4. How does exception handling in Python differ from Java? Also, list the optional clauses for a <try-except> block in Python?

Ans. Unlike Java, Python implements exception handling in a bit different way. It provides an option of using a <try-except> block where the programmer can see the error details without terminating the program. Sometimes, along with the problem, this <try-except> statement offers a solution to deal with the error.

There are following clauses available in Python language.

1. try-except-finally

2. try-except-else

5. What do you know about the <list> and <dict> comprehensions? Explain with an example.

Ans. The <List/Dict> comprehensions provide an easier way to create the corresponding object using the existing iterable. As per official Python documents, the list comprehensions are usually faster than the standard loops. But it’s something that may change between releases.

The <List/Dict> Comprehensions Examples.

#Simple Iteration

item = []

for n in range(10):

item.append(n*2)

print item

#List Comprehension

item = [n*2 for n in range(10)]

print item

Both the above example would yield the same output.

Python 2.7.10 (default, Jul 14 2015, 19:46:27)

[GCC 4.8.2] on linux

[0, 2, 4, 6, 8, 10, 12, 14, 16, 18] 

#Dict Comprehension

item = {n: n*2 for n in range(10)}

print item

Python 2.7.10 (default, Jul 14 2015, 19:46:27)

[GCC 4.8.2] on linux

{0: 0, 1: 2, 2: 4, 3: 6, 4: 8, 5: 10, 6: 12, 7: 14, 8: 16, 9: 18}

6. What are the methods you know to copy an object in Python?

Ans. Commonly, we use <copy.copy()> or <copy.deepcopy()> to perform copy operation on objects. Though not all objects support these methods but most do.

But some objects are easier to copy. Like the dictionary objects provide a <copy()> method.

Example.

item = {n: n*2 for n in range(10)}

newdict = item.copy()

print newdict

7. Can you write code to determine the name of an object in Python?

Ans. No objects in Python have any associated names. So there is no way of getting the one for an object. The assignment is only the means of binding a name to the value. The name then can only refer to access the value. The most we can do is to find the reference name of the object.

Example.

class Test:

    def __init__(self, name):

self.cards = []

self.name = name

    def __str__(self):

return '{} holds ...'.format(self.name)

obj1 = Test('obj1')

print obj1

obj2 = Test('obj2')

print obj2

8. Can you write code to check whether the given object belongs to a class or its subclass?

Ans. Python has a built-in method to list the instances of an object that may consist of many classes. It returns in the form of a table containing tuples instead of the individual classes. Its syntax is as follows.

<isinstance(obj, (class1, class2, ...))>

The above method checks the presence of an object in one of the classes. The built-in types can also have many formats of the same function like <isinstance(obj, str)> or <isinstance(obj, (int, long, float, complex))>.

Also, it’s not recommended to use the built-in classes. Create an user-defined class instead.

We can take the following example to determine the object of a particular class.

Example.

def lookUp(obj):

    if isinstance(obj, Mailbox):

print "Look for a mailbox"

elif isinstance(obj, Document):

print "Look for a document"

     else:

print "Unidentified object"

Python interview questions and answers for testers

Python Programming Language Interview Questions have been designed specially to get you acquainted with the nature of questions you may encounter during your interview preparations for the subject of Python Programming Language. Here is the different kind of question to hone your skills.

1) How are arguments passed by value or by reference?

Everything in Python is an object and all variables hold references to the objects. The references values are according to the functions; as a result you cannot change the value of the references. However, you can change the objects if it is mutable.

2) What is Dict and List comprehensions are?

They are syntax constructions to ease the creation of a Dictionary or List based on existing iterable.

3) What are the built-in type does python provides?

There are mutable and Immutable types of Pythons built in types Mutable built-in types

List

Sets

Dictionaries

Immutable built-in types

Strings

Tuples

Numbers

4) What is namespace in Python?

In Python, every name introduced has a place where it lives and can be hooked for. This is known as namespace. It is like a box where a variable name is mapped to the object placed. Whenever the variable is searched out, this box will be searched, to get corresponding object.

5) What is lambda in Python?

It is a single expression anonymous function often used as inline function.

Python coding interview questions and answers

Set of Python Interview Questions for all the developers & aspirants who are going to attempt Python Interview,

1) What is <Yield> Keyword in Python?

The <yield> keyword in Python can turn any function into a generator. Yields work like a standard return keyword.

But it’ll always return a generator object. Also, a function can have multiple calls to the <yield> keyword.

Example:

def testgen(index):

weekdays = ['sun','mon','tue','wed','thu','fri','sat']

yield weekdays[index]

yield weekdays[index+1]

day = testgen(0)

print next(day), next(day)

Output: sun mon

2) How to convert a list into a string?

When we want to convert a list into a string, we can use the <”.join()> method which joins all the elements into one and returns as a string.

Example:

weekdays = ['sun','mon','tue','wed','thu','fri','sat']

listAsString = ' '.join(weekdays)

print(listAsString)P

3) How to convert a list into a tuple?

A) By using Python <tuple()> function we can convert a list into a tuple. But we can’t change the list after turning it into tuple, because it becomes immutable.

Example:

weekdays = ['sun','mon','tue','wed','thu','fri','sat']

listAsTuple = tuple(weekdays)

print(listAsTuple)

output: (‘sun’, ‘mon’, ‘tue’, ‘wed’, ‘thu’, ‘fri’, ‘sat’)

4) How to convert a list into a set?

A) User can convert list into set by using <set()> function.

Example:

weekdays = ['sun','mon','tue','wed','thu','fri','sat','sun','tue']

listAsSet = set(weekdays)

print(listAsSet)

output: set([‘wed’, ‘sun’, ‘thu’, ‘tue’, ‘mon’, ‘fri’, ‘sat’])

5) How to count the occurrences of a particular element in the list?

A) In Python list, we can count the occurrences of an individual element by using a <count()> function.

Example # 1:

weekdays = ['sun','mon','tue','wed','thu','fri','sun','mon','mon']

print(weekdays.count('mon'))

Output: 3

Example # 2:

weekdays = ['sun','mon','tue','wed','thu','fri','sun','mon','mon']

print([[x,weekdays.count(x)] for x in set(weekdays)])

output: [[‘wed’, 1], [‘sun’, 2], [‘thu’, 1], [‘tue’, 1], [‘mon’, 3], [‘fri’, 1]]

Python coding questions

Here are set of codings to know your programming skills. Do the programming and check out the output to explore the knowledge. 

Click here python course to become a python developer

1) What is the output of the below program?

>>>names = ['Chris', 'Jack', 'John', 'Daman']

>>>print(names[-1][-1])

A) The output is: n

2) What is Enumerate() Function in Python?

A) The Python enumerate() function adds a counter to an iterable object. enumerate() function can accept sequential indexes starting from zero.

Python Enumerate Example:

subjects = ('Python', 'Interview', 'Questions')

for i, subject in enumerate(subjects):

print(i, subject)

Output:

0 Python

1 Interview

2 Questions

3) What is data type SET in Python and how to work with it?

A) The Python data type “set” is a kind of collection. It has been part of Python since version 2.4. A set contains an unordered collection of unique and immutable objects.

# *** Create a set with strings and perform a search in set

objects = {"python", "coding", "tips", "for", "beginners"}

# Print set.

print(objects)

print(len(objects)) 

# Use of "in" keyword.

if "tips" in objects:

print("These are the best Python coding tips.")

# Use of "not in" keyword.

if "Java tips" not in objects:

print("These are the best Python coding tips not Java tips.")

# ** Output

{'python', 'coding', 'tips', 'for', 'beginners'}

5

These are the best Python coding tips.

These are the best Python coding tips not Java tips.

# *** Lets initialize an empty set

items = set()

# Add three strings.

items.add("Python")

items.add("coding")

items.add("tips") 

print(items)

# ** Output

{'Python', 'coding', 'tips'}

4) How do you Concatenate Strings in Python?

A) We can use ‘+’ to concatenate strings.

Python Concatenating Example:

# See how to use ‘+’ to concatenate strings.

>>> print('Python' + ' Interview' + ' Questions')

# Output:

Python Interview Questions

5) How to generate random numbers in Python?

A) We can generate random numbers using different functions in Python. They are:

#1. random() – This command returns a floating point number, between 0 and 1.

#2. uniform(X, Y) – It returns a floating point number between the values given as X and Y.

#3. randint(X, Y) – This command returns a random integer between the values given as X and Y.

Cracking python interview questions on programming

These are the top questions in python to crack in the interview.  Read the questions and try answering all to check your knowledge.

1) Can Python be used for web client and web server side programming? And which one is best suited to Python

Answer: Python is best suited for web server-side application development due to its vast set of features for creating business logic, database interactions, web server hosting, etc. 

However, Python can be used as a web client-side application that needs some conversions for a browser to interpret the client-side logic. Also, note that Python can be used to create desktop applications that can run as a standalone application such as utilities for test automation.

2) Mention at least 3-4 benefits of using Python over the other scripting languages such as Javascript.

Answer: Enlisted below are some of the benefits of using Python.

Application development is faster and easy.

Extensive support of modules for any kind of application development including data analytics/machine learning/math-intensive applications.

An excellent support community to get your answers.

3) Explain List, Tuple, Set, and Dictionary and provide at least one instance where each of these collection types can be used.

Answer:

List: Collection of items of different data types that can be changed at run time.

Tuple: Collection of items of different data types that cannot be changed. It only has read-only access to the collection. This can be used when you want to secure your data collection set and does not need any modification.

Set: Collection of items of a similar data type.

Dictionary: Collection of items with key-value pairs.

Generally, List and Dictionary are extensively used by programmers as both of them provide flexibility in data collection.

4) Does Python allow you to program in a structured style?

Answer: Yes. It does allow to code in a structured as well as Object-oriented style. It offers excellent flexibility to design and implement your application code depending on the requirements of your application.

5) What is PIP software in the Python world?

 Answer: PIP is an acronym for Python Installer Package which provides a seamless interface to install various Python modules. It is a command-line tool that can search for packages over the internet and install them without any user interaction.

python interview questions for data science

Data science goes beyond simple data analysis and requires that you be able to work with more advanced tools. Thus, if you work with big data and need to perform complex computations or create aesthetically pleasing and interactive plots, Python is one of the most efficient solutions out there.

Python’s readability and simple syntax make it relatively easy to learn, even for non-programmers. Moreover, Python has plenty of data analysis libraries that make your work easier.

Of course, Python requirements for data scientists are different from those for software engineers and developers. Data scientists should be comfortable with basic Python syntax, built-in data types, and the most popular libraries for data analysis. These are the topics that are usually covered in the Python interview questions for data science.

1. What are the data types used in Python?

Python has the following built-in data types:

Number (float, integer)

String

Tuple

List

Set

Dictionary

Numbers, strings, and tuples are immutable data types, meaning they cannot be modified during runtime. Lists, sets, and dictionaries are mutable, which means they can be modified during runtime.

2. Explain the difference between lists and tuples.

Both lists and tuples are made up of elements, which are values of any Python data type. However, these data types have a number of differences:

Lists are mutable, while tuples are immutable.

Lists are created with square brackets (e.g., my_list = [a, b, c]), while tuples are enclosed in parentheses (e.g., my_tuple = (a, b, c)).

Lists are slower than tuples.

3. What is a Python dictionary?

A dictionary is one of the built-in data types in Python. It defines an unordered mapping of unique keys to values. Dictionaries are indexed by keys, and the values can be any valid Python data type (even a user-defined class). Notably, dictionaries are mutable, which means they can be modified. A dictionary is created with curly braces and indexed using the square bracket notation.

Here’s an example:

my_dict = {'name': 'Hugh Jackman', 'age': 50, 'films': ['Logan', 'Deadpool 2', 'The Front Runner']}

my_dict['age']

Here, the keys include name, age, and films. As you can see, the corresponding values can be of different data types, including numbers, strings, and lists. Notice how the value 50 is accessed via the corresponding key age.

4. Explain list comprehensions and how they’re used in Python.

List comprehensions provide a concise way to create lists.

A list is traditionally created using square brackets. But with a list comprehension, these brackets contain an expression followed by a for clause and then if clauses, when necessary. Evaluating the given expression in the context of these for and if clauses produces a list.

It’s best explained with an example:

old_list = [1, 0, -2, 4, -3]

new_list = [x**2 for x in old_list if x > 0]

print(new_list)

[1,16]

Here, we’re creating a new list by taking the elements of the old list to the power of 2, but only for the elements that are strictly positive. The list comprehension allows us to solve this task in just one line of code.

5. What is a negative index, and how is it used in Python?

A negative index is used in Python to index a list, string, or any other container class in reverse order (from the end). Thus, [-1] refers to the last element, [-2] refers to the second-to-last element, and so on.

Here are two examples:

list = [2, 5, 4, 7, 5, 6, 9]

print (list[-1])

9

text = "I love data science"

print (text[-3])

n

 

Python interview questions and answers for mcq

Learn Python Multiple Choice Questions and Answers with explanations. Practice Python MCQs Online Quiz Mock Test For Objective Interview. Are you preparing for the interviews based on the Python language? Python Questions and Answers for beginners are arranged in this article for the sake of contenders. 

The applicants can refer to the last portion of this page to find the Python Online Test. By checking and referring to the Python MCQ Quiz, the applicants can prepare for the interviews and the entrance examinations. Python Quiz Questions and Answers are asked in the previous examinations and may be repeated in the upcoming tests. So, the postulates can check and practice the multiple choice questions related to the Python with the help of this post. Python MCQ'S are available in the below Python Mock Test to prepare for the examinations.

1.What is the output when following code is executed?

print r"\nhello"

The output is

A. a new line and hello

B. \nhello

C. the letter r and then hello

D. Error

Answer: Option B

Explanation:

When prefixed with the letter ‘r’ or ‘R’ a string literal becomes a raw string and the escape sequences such as \n are not converted.

2.What is the output of the following code?

example = "snow world"

example[3] = 's'

print example

A. snow

B. snow world

C. Error

D. snos world

Answer: Option C

Explanation:

Strings cannot be modified.

3. What is the output of “hello” +1+2+3?

A. hello123

B. hello

C. Error

D. hello6

Answer: Option C

Explanation:

Cannot concantenate str and int objects.

4.Suppose i is 5 and j is 4, i+j is same as

A. i.__add(j)

B. i.__add__(j)

C. i.__Add(j)

D. i.__ADD(j)

Answer: Option B

Explanation: 

Execute in shell to verify.

5. Which of the following statements is used to create an empty set? 

A. { }

B. set()

C. [ ].

D. ( )

Answer: Option B

Explanation: 

{ } creates a dictionary not a set. Only set() creates an empty set.

Technical Python Interview Questions and Answers

If you strong with the coding check it out with the technical part. Here are set of top technical questions which will help you to crack the interview in the easier way.

1) What is recursion?

 When a function makes a call to itself, it is termed recursion. But then, in order for it to avoid forming an infinite loop, we must have a base condition.

Let’s take an example.

>>> def facto(n):

if n==1: return 1

return n*facto(n-1)

>>> facto(4)

2) How do you calculate the length of a string?

 This is simple. We call the function len() on the string we want to calculate the length of.

>>> len('Ayushi Sharma')

3). What is a control flow statement?

A Python program usually starts to execute from the first line. From there, it moves through each statement just once and as soon as it’s done with the last statement, it transactions the program. However, sometimes, we may want to take a more twisted path through the code. Control flow statements let us disturb the normal execution flow of a program and bend it to our will.

4). How do we execute Python?

 Python files first compile to bytecode. Then, the host executes them.

5. Explain Python’s parameter-passing mechanism.

 To pass its parameters to a function, Python uses pass-by-reference. If you change a parameter within a function, the change reflects in the calling function. This is its default behavior. However, when we pass literal arguments like strings, numbers, or tuples, they pass by value. This is because they are immutable.

Python OOPS Interview Questions and Answers

 You might be strong with object oriented programming language. Here are set of python object oriented programming language questions to hone your skills

1) What makes Python object-oriented?

 Again the frequently asked Python Interview Question

Python is object-oriented because it follows the Object-Oriented programming paradigm. This is a paradigm that revolves around classes and their instances (objects). With this kind of programming, we have the following features:

Encapsulation

Abstraction

Inheritance

Polymorphism

Data hiding

2) How many types of objects does Python support?

Objects in Python are mutable and immutable. Let’s talk about these.

Immutable objects- Those which do not let us modify their contents. Examples of these will be tuples, booleans, strings, integers, floats, and complexes. Iterations on such objects are faster.

>>> tuple=(1,2,4)

>>> tuple

(1, 2, 4)

>>> 2+4j

(2+4j)

Mutable objects – Those that let you modify their contents. Examples of these are lists, sets, and dicts. Iterations on such objects are slower.

>>> [2,4,9]

[2, 4, 9]

>>> dict1={1:1,2:2}

2.>>> dict1

{1: 1, 2: 2}

While two equal immutable objects’ reference variables share the same address, it is possible to create two mutable objects with the same content.

Top Python Interview Questions and Answers

Once you’ve had enough understanding of the various concepts of Python, it’s time to give a shot at some interviews. To increase your chances of clearing them, here is a list of top Python interview questions that you must know answers to:

1. What are the distinct features of Python?

Answer: The distinct features of Python include the following.

Structured and functional programmings are supported.

It can be compiled to byte-code for creating larger applications.

Develops high-level dynamic data types.

Supports checking of dynamic data types.

Applies automated garbage collection.

It could be used effectively along with Java, COBRA, C, C++, ActiveX, and COM.

2. What is Pythonpath?

Answer: A Pythonpath tells the Python interpreter to locate the module files that can be imported into the program. It includes the Python source library directory and source code directory.

3. Can we preset Pythonpath?

Answer: Yes, we can preset Pythonpath as a Python installer.

4. Why do we use Pythonstartup environment variable?

Answer: We use the Pythonstartup environment variable because it consists of the path in which the initialization file carrying Python source code can be executed to start the interpreter. 

5. What is the Pythoncaseok environment variable?

Answer: Pythoncaseok environment variable is applied in Windows with the purpose to direct Python to find the first case insensitive match in an import statement.

6. What are the positive and negative indices?

Answer:  In the positive indices are applied the search beings from left to the right. In the case of the negative indices, the search begins from right to left. For example, in the array list of size n the positive index, the first index is 0, then comes 1 and until the last index is n-1. However, in the negative index, the first index is -n, then -(n-1) until the last index will be -1.

7. What can be the length of the identifier in Python?

Answer: The length of the identifier in Python can be of any length. The longest identifier will violate from PEP – 8 and PEP – 20

8. Define Pass statement in Python?

Answer: A Pass statement in Python is used when we cannot decide what to do in our code, but we must type something for making syntactically correct.

9.What are the limitations of Python?

Answer: There are certain limitations of Python, which include the following:

It has design restrictions.

It is slower when compared with C and C++ or Java.

It is inefficient in mobile computing.

It consists of an underdeveloped database access layer.

10. Do runtime errors exist in Python? Give an example?

Answer: Yes, runtime errors exist in Python. For example, if you are duck typing and things look like a duck, then it is considered as a duck even if that is just a flag or stamp or any other thing. The code, in this case, would be A Run-time error. For example, Print “Hack io”, then the runtime error would be the missing parenthesis that is required by print ( ).

11. Why do we need a break in Python?

Answer: Break helps in controlling the Python loop by breaking the current loop from execution and transfer the control to the next block.

12. Why do we need a continue in Python?

Answer: A continue also helps in controlling the Python loop but by making jumps to the next iteration of the loop without exhausting it.

13. Can we use a break and continue together in Python? How?

Answer:  Break and continue can be used together in Python. The break will stop the current loop from execution, while jump will take to another loop.

14. Does Python support an intrinsic do-while loop?

Answer: No Python does not support an intrinsic do-while loop.

15. How many ways can be applied for applying reverse string?

Answer: There are five ways in which the reverse string can be applied which include the following.

Loop

Recursion

Stack

Extended Slice Syntax

Reversed

16. What are the different stages of the Life Cycle of a Thread?

Answer: The different stages of the Life Cycle of a Thread can be stated as follows.

Stage 1: Creating a class where we can override the run method of the Thread class.

Stage 2: We make a call to start() on the new thread. The thread is taken forward for scheduling purposes.

Stage 3: Execution takes place wherein the thread starts execution, and it reaches the running state.

Stage 4: Thread wait until the calls to methods including join() and sleep() takes place. 

Stage 5: After the waiting or execution of the thread, the waiting thread is sent for scheduling.

Stage 6: Running thread is done by executing the terminates and reaches the dead state.

17. What is the purpose of relational operators in Python?

Answer: The purpose of relational operators in Python is to compare values.

18. What are assignment operators in Python?

Answer: The assignment operators in Python can help in combining all the arithmetic operators with the assignment symbol.

19. Draw a comparison between the range and xrange in Python?

Answer: In terms of functionality, both range and xrange are identical. Both allow for generating a list of integers. The main difference between the two is that while range returns a Python list object, xrange returns an xrange object.

Xrange is not able to generate a static list at runtime the way range does. On the contrary, it creates values along with the requirements via a special technique called yielding. It is used with a type of object known as generators.

If you have a very enormous range for which you need to generate a list, then xrange is the function to opt for. This is especially relevant for scenarios dealing with a memory-sensitive system, such as a smartphone.

The range is a memory beast. Using it requires much more memory, especially if the requirement is gigantic. Hence, in creating an array of integers to suit the needs, it can result in a Memory Error and ultimately lead to crashing the program.

20. Explain Inheritance and its various types in Python?

Answer: Inheritance enables a class to acquire all the members of another class. These members can be attributes, methods, or both. By providing reusability, inheritance makes it easier to create as well as maintain an application.

The class which acquires is known as the child class or the derived class. The one that it acquires from is known as the superclass or base class or the parent class. There are 4 forms of inheritance supported by Python:

Single Inheritance – A single derived class acquires from on single superclass.

Multi-Level Inheritance – At least 2 different derived classes acquire from two distinct base classes.

Hierarchical Inheritance – A number of child classes acquire from one superclass

Multiple Inheritance – A derived class acquires from several superclasses.

21. How will you differentiate between deep copy and shallow copy?

Answer: We use a shallow copy when a new instance type gets created. It keeps the values that are copied in the new instance. Just like it copies the values, the shallow copy also copies the reference pointers.

Reference points copied in the shallow copy reference to the original objects. Any changes made in any member of the class affect the original copy of the same. Shallow copy enables faster execution of the program.

Deep copy is used for storing values that are already copied. Unlike shallow copy, it doesn’t copy the reference pointers to the objects. Deep copy makes the reference to an object in addition to storing the new object that is pointed by some other object.

Changes made to the original copy will not affect any other copy that makes use of the referenced or stored object. Contrary to the shallow copy, deep copy makes execution of a program slower. This is due to the fact that it makes some copies for each object that is called.

22. What do you understand by the process of compilation and linking in Python?

Answer: In order to compile new extensions without any error, compiling and linking is used in Python. Linking initiates only and only when the compilation is complete.

In the case of dynamic loading, the process of compilation and linking depends on the style that is provided with the concerned system. In order to provide dynamic loading of the configuration setup files and rebuilding the interpreter, the Python interpreter is used.

23. What is Flask and what are the benefits of using it?

Answer: Flask is a web microframework for Python with Jinja2 and Werkzeug as its dependencies. As such, it has some notable advantages:

Flask has little to no dependencies on external libraries

Because there is a little external dependency to update and fewer security bugs, the web microframework is lightweight to use.

Features an inbuilt development server and a fast debugger.

24. What is the map() function used for in Python?

Answer: The map() function applies a given function to each item of an iterable. It then returns a list of the results. The value returned from the map() function can then be passed on to functions to the likes of the list() and set().

Typically, the given function is the first argument and the iterable is available as the second argument to a map() function. Several tables are given if the function takes in more than one arguments.

25. What is Pickling and Unpickling in Python?

Answer: The Pickle module in Python allows accepting any object and then converting it into a string representation. It then dumps the same into a file by means of the dump function. This process is known as pickling.

The reverse process of pickling is known as unpickling i.e. retrieving original Python objects from a stored string representation.

Python interview question pdf

Python is an interpreted language. Set of questions are given below for you to know more about it. Get it done to get stronger in python programming language.

1. What is Python? What are the benefits of using Python?

Ans: Python is a programming language with objects, modules, threads, exceptions and automatic memory management. The benefits of pythons are that it is simple and easy, portable, extensible, build-in data structure and it is an open source.

2. What is PEP 8?

Ans: PEP 8 is a coding convention, a set of recommendation, about how to write your Python code more readable.

3. Explain how can you make a Python Script executable on Unix?To make a Python Script executable on Unix, you need to do two things,

Ans: Script file’s mode must be executable and

the first line must begin with # ( #!/usr/local/bin/python)

4. How can you share global variables across modules?

Ans: To share global variables across modules within a single program, create a special module. Import the config module in all modules of your application. The module will be available as a global variable across modules.

5. Explain how can you access a module written in Python from C?

Ans: You can access a module written in Python from C by following method, Module = =PyImport_ImportModule(“”);

6. Mention the use of // operator in Python?

Ans: It is a Floor Divisionoperator , which is used for dividing two operands with the result as quotient showing only digits before the decimal point. For instance, 10//5 = 2 and 10.0//5.0 = 2.0.

7. Mention what is the difference between Django, Pyramid, and Flask?

Ans: Flask is a “micro framework” primarily build for a small application with simpler requirements. In flask, you have to use external libraries. Flask is ready to use.

Pyramid are build for larger applications. It provides flexibility and lets the developer use the right tools for their project. The developer can choose the database, URL structure, templating style and more. Pyramid is heavy configurable.

Like Pyramid, Django can also used for larger applications. It includes an ORM.

8. Mention what is Flask-WTF and what are their features?

Ans: Flask-WTF offers simple integration with WTForms. Features include for Flask WTF are

Integration with wtforms Secure form with csrf token Global csrf protection Internationalization integration Recaptcha supporting

File upload that works with Flask Uploads

9. Explain what is the common way for the Flask script to work?

 Ans: The common way for the flask script to work is…

Either it should be the import path for your application Or the path to a Python file

10. Explain how you can access sessions in Flask?

Ans: A session basically allows you to remember information from one request to another. In a flask, it 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.

11. What type of a language is pythTop on? Interpreted or Compiled?

 Ans: Beginner’s Answer:

Python is an interpreted, interactive, objectoriented programming language.

Expert Answer:

Python is an interpreted language, as opposed to a compiled one, though the

distinction can be blurry because of the presence of the bytecode compiler. This means

that source files can be run directly without explicitly crTop eating an executable which is

then run.

12. What do you mean by python being an “interpreted language”? (Continues from previous question)

 Ans: An interpreted language​is a programming language​for which most of its

implementations execute instructions directly, without previously compiling a program

into machinelanguage​instructions. In context of Python, it means that Python program

runs directly from the source code.

Top 13.What is python’s standard way of identifying a block of code?

Ans: Indentation.

14. provide an example implementation of a function called “my_func” that returns the square of a given variable “x”. (Continues from previous question)

Ans:

defmy_func(x):

returnx**2

15. Is python statically typed or dynamically typed?

Ans: ​Dynamic.

In a statically typed language, the type of variables must be known (and usually

declared) at the point at which it is used. Attempting to use it will be an error. In a

dynamically typed language, objects still have a type, but it is determined at runtime.

You are free to bind names (variables) to different objects with a different type. So long

as you only perform operations valid for the type the interpreter doesn’t care what type

they actually are.

16. Is python strongly typed or weakly typed language?

Ans: ​Strong.

In a weakly typed language a compiler / interpreter will sometimes change the

type of a variable. For example, in some languages (like JavaScript) you can add

strings to numbers ‘x’ + 3 becomes ‘x3’. This can be a problem because if you have

made a mistake in your program, instead of raising an exception execution will continue

but your variables now have wrong and unexpected values. 

In a strongly typed

language (like Python) you can’t perform operations inappropriate to the type of the

object  attempting to add numbers to strings will fail. Problems like these are easier to

diagnose because the exception is raised at the point where the error occurs rather than

at some other, potentially far removed, place.

17. What is the python syntax for switch case statements?

Ans: Python doesn’t support switchcase statements. You can use ifelse statements

for this purpose.

18. What are the rules for local and global variables in Python?

Ans: If a variable is defined outside function then it is implicitly global​. If variable is

assigned new value inside the function means it is local​. If we want to make it global we

need to explicitly define it as global. Variable referenced inside the function are implicit

global​.

19. What is the output of the following program?

Ans: 

#!/usr/bin/python

deffun1(a):

print’a:’,a

a=33;

print’locala:’,a

a=100

fun1(a)

print’aoutsidefun1:’,a

Ans. Output:

a:100

locala:33

aoutsidefun1:100

FAQs

1. How do I prepare for a Python developer interview?

You should set aside some time right away to learn at least the fundamentals of Python, and keep in mind that unless you have years of expertise with another high-level, object-oriented programming language (e.g., Java, JavaScript, C#, etc...). This is the best way to prepare for python developer interview.

2. What are the interview questions for Python developer?

• What is Python? What are the benefits of using Python? 
• What is PEP 8? 
• What are pickling and unpickling?

3. What are the 10 most common interview questions and answers for freshers?

1. What are your 2 good and 2 bad qualities
2. Where do you see yourself in next five years
3. What are you passionate about, if you were not working what would you like to pursue
4. If you are not selected, what would you be doing in next 3 months
5. What is important to you in a job learning or money ?
6. On behaviour - what are your strengths and weaknesses ?
7. How do you control your anger / emotions ?
8. Are you an introvert or extrovert - asked for client facing, sales and marketing jobs
9. What are your hobbies ?
10. What do you do in your spare time ??

4. How would you describe a Python project in interview?

In a Python interview, choose the project that you are most proud of and confidently explain it. Begin your explanation of the project by stating the problem. Explain how you came up with the solution and the steps you took to get there. Also, describe the roadblocks you encountered and how you overcame them.

5. Who uses Python?

Python is mostly used for automation programmes, and it is frequently used with Django for Web development. Then there's Google, which employs Python extensively in several of its initiatives. Python can also be used for data science. Python is a programming language that is frequently used in scientific and numerical computing.