Python was developed by Guido van Rossum and was introduced first on 20 February 1991. It is one of the most widely used programming languages which provides flexibility to incorporate dynamic semantics. It is an open-source and free language having clean and simple syntax. All these things make it easy for developers to learn and understand Python. Python also supports object-based programming and is mainly used for doing general-purpose programming.
Due to its simplicity and the capacity to achieve numerous functionalities in fewer lines of code, the popularity of Python is increasing exponentially. It is also used in artificial intelligence, machine learning, web scraping, web development, and different other domains due to its ability to support powerful computations through powerful libraries. As a result, Python Developers are in high demand in India and around the world. Companies provide these Developers with incredible remunerations and bonuses.
Here are some Python Interview Questions and Answers:
1. What is Python?
Python is a highly comprehensive, interactive, and object-oriented scriptwriting language. It is specifically developed with the purpose of making the content highly readable among net surfers. Python makes use of various English keywords other than just punctuations. It also has lesser syntactical constructions like in other languages. Additionally, python supports objects, modules, threads, exception-handling, and automatic memory management which help in modeling real-world problems and building applications to solve these problems.
2. What are the distinct features of Python?
The distinct features of Python include the following.
- Structured and functional programs 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.
3. What are the advantages of Python?
Python is a general-purpose dynamic programming language that is high-level and interpreted. Its architectural framework prioritizes code readability and utilizes indentation extensively.
- Third-party modules are present.
- Several support libraries are available (NumPy for numerical calculations, Pandas for data analytics, etc)
- Community development and open source
- Adaptable, simple to read, learn, and write
- Data structures that are pretty easy to work on
- High-level language
- The language that is dynamically typed (No need to mention data type based on the value assigned, it takes data type)
- Object-oriented programming language
- Interactive and transportable
- Ideal for prototypes since it allows you to add additional features with minimal code.
- Highly Effective
- Internet of Things (IoT) Possibilities
- Portable Interpreted Language across Operating Systems
- Since it is an interpreted language it executes any code line by line and throws an error if it finds something missing.
- Python is free to use and has a large open-source community.
- Python has a lot of support for libraries that provide numerous functions for doing any task at hand.
- One of the best features of Python is its portability: it can and does run on any platform without having to change the requirements.
- Provides a lot of functionality in lesser lines of code compared to other programming languages like Java, C++, etc.
4. What are the Benefits of using Python?
- Python is a general-purpose programming language that has a simple, easy-to-learn syntax that emphasizes readability and therefore reduces the cost of program maintenance. Moreover, the language is capable of scripting, is completely open-source, and supports third-party packages encouraging modularity and code reuse.
- Its high-level data structures, combined with dynamic typing and dynamic binding, attract a huge community of developers for Rapid Application Development and deployment.
5. What are the applications of Python?
Python is notable for its general-purpose character, which allows it to be used in practically any software development sector. Python may be found in almost every new field. It is the most popular programming language and may be used to create any application.
- Web Applications
- Desktop GUI Applications
- Console-based Application
- Software Development
- Scientific and Numeric
- Business Applications
- Audio or Video-based Applications
- 3D CAD Applications
- Enterprise Applications
- Image Processing Application
6. What is Pythonpath?
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.
7. Can we preset Pythonpath?
Yes, we can preset Pythonpath as a Python installer.
8. Why do we use Pythonstartup environment variable?
We use the Python startup environment variable because it consists of the path in which the initialization file carrying Python source code can be executed to start the interpreter.
9. What is the Pythoncaseok environment variable?
Pythoncaseok environment variable is applied in Windows with the purpose to direct Python to find the first case insensitive match in an import statement.
10. What are the supported standard data types in Python?
The supported standard data types in Python include the following.
- List.
- Number.
- String.
- Dictionary.
- Tuples.
11. Define tuples in Python?
Tuples are a sequence data type in Python. The number of values in tuples is separated by commas.
12. What is the major difference between tuples and lists in Python?
There are several major differences between tuples and lists in Python, which include the following:
| Tuples | Lists |
| Tuples are similar to a list, but they are enclosed within parenthesis, unlike the list. | The list is used to create a sequence. |
| The element and size can be changed. | The element and size cannot be changed. |
| They cannot be updated. | They can be updated. |
| They act as read-only lists. | They act as a changeable list. |
| Tuples are surrounded by ( ) | Lists are surrounded by [ ] |
| Example of Tuple Code is, tup = (1, “a”, “string”, 1+2) | Example of Lists Code is, L = [1, “a” , “string” , 1+2] |
13. What are the positive and negative indices?
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.
14. What can be the length of the identifier in Python?
The length of the identifier in Python can be of any length. The longest identifier will violate PEP – 8 and PEP – 20.
15. Define the Pass statement in Python?
A Pass statement in Python is used when we cannot decide what to do in our code, but we must type something for making it syntactically correct.
16. What are the limitations of Python?
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.
17. Do runtime errors exist in Python? Give an example?
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 “Youngster Company”, then the runtime error would be the missing parenthesis that is required by print ( ).
18. Why do we need a break in Python?
The break helps in controlling the Python loop by breaking the current loop from execution and transferring the control to the next block.
19. Why do we need a continue in Python?
A continue also helps in controlling the Python loop but by making jumps to the next iteration of the loop without exhausting it.
20. Can we use a break and continue together in Python? How?
Break and continue can be used together in Python. The break will stop the current loop from execution, while the jump will take to another loop.
21. Does Python support an intrinsic do-while loop?
No Python does not support an intrinsic do-while loop.
22. How many ways can be applied for applying reverse string?
There are five ways in which the reverse string can be applied which include the following.
- Loop
- Recursion
- Stack
- Extended Slice Syntax
- Reversed
23. What are the different stages of the Life Cycle of a Thread?
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() take 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 reaching the dead state.
24. What is the purpose of relational operators in Python?
The purpose of relational operators in Python is to compare values.
25. What are assignment operators in Python?
The assignment operators in Python can help in combining all the arithmetic operators with the assignment symbol.
26. Why do we need membership operators in Python?
We need membership operators in Python with the purpose to confirm if the value is a member in another or not.
Practical Questions
27. What is slicing in Python?
- As the name suggests, ‘slicing’ is taking parts.
- Syntax for slicing is [start : stop : step]
- Start is the starting index from where to slice a list or tuple
- Stop is the ending index or where to sop.
- Step is the number of steps to jump.
- Default value for start is 0, stop is number of items, step is 1.
- Slicing can be done on strings, arrays, lists, and tuples.
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
print(numbers[1 : : 2]) #output : [2, 4, 6, 8, 10]28. How do you debug a Python program?
By using this command we can debug a python program:
$ python -m pdb python-script.py
29. 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
30. 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
31. How to convert a list into a tuple?
By using Python <tuple()> function we can convert a list into a tuple. But we can’t change the list after turning it into a 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’)
32. How to convert a list into a set?
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'])
33. How to count the occurrences of a particular element in the list?
In the 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]]
34. How can you create an Empty NumPy Array In Python?
We can create an Empty NumPy Array in two ways in Python,
1) import numpy numpy.array([]) 2) numpy.empty(shape=(0,0))
35. What is the output of the below code?
>>> import array >>> a = [1, 2, 3] >>> print a[-3] >>> print a[-2] >>> print a[-1]
Output:
3, 2, 1
36. Write a Python Program to Check if a Number is a Palindrome or not?
Python Program to Check if a Number is a Palindrome or Not:
n=int(input("Enter number:"))
temp=n
rev=0
while(n>0):
dig=n%10
rev=rev*10+dig
n=n//10
if(temp==rev):
print("The number is a palindrome!")
else:
print("The number isn't a palindrome!")
Output:
Enter number:151
The number is a palindrome!
37. Write a Python Program to Count the Number of Digits in a Number?
Python Program to Count the Number of Digits in a Number:
n=int(input("Enter number:"))
count=0
while(n>0):
count=count+1
n=n//10
print("The number of digits in the number is:",count)
Output:
Enter number:14325
The number of digits in the number is: 5
38. Write a Python Program to Print Table of a Given Number?
Python Program to Print Table of a Given Number:
n=int(input("Enter the number to print the tables for:"))
for i in range(1,11):
print(n,"x",i,"=",n*i)
Output:
Enter the number to print the tables for:7
7 x 1 = 7
7 x 2 = 14
7 x 3 = 21
7 x 4 = 28
7 x 5 = 35
7 x 6 = 42
7 x 7 = 49
7 x 8 = 56
7 x 9 = 63
7 x 10 = 70
39. Write a Python Program to Check if a Number is a Prime Number?
Python Program to Check if a Number is a Prime Number:
a=int(input("Enter number: "))
k=0
for i in range(2,a//2+1):
if(a%i==0):
k=k+1
if(k<=0):
print("Number is prime")
else:
print("Number isn't prime")
Output:
Enter number: 7
Number is prime
40. Write a Python Program to Check if a Number is an Armstrong Number?
Python Program to Check if a Number is an Armstrong Number:
n=int(input("Enter any number: "))
a=list(map(int,str(n)))
b=list(map(lambda x:x**3,a))
if(sum(b)==n):
print("The number is an armstrong number. ")
else:
print("The number isn't an arsmtrong number. ")
Output:
Enter any number: 371
The number is an armstrong number.