Top MNC Interview Questions and Answers – Python

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

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?

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

3) What is pickling and unpickling?

Pickle module accepts any Python object and converts it into a string representation and dumps it into a file by using dump function, this process is called pickling. While the process of retrieving original Python objects from the stored string representation is called unpickling.

4) How Python is interpreted?

Python language is an interpreted language. Python program runs directly from the source code. It converts the source code that is written by the programmer into an intermediate language, which is again translated into machine language that has to be executed.

5) What are tuples in Python?

A tuple is another sequence data type that is similar to the list. A tuple consists of a number of values separated by commas. Unlike lists, however, tuples are enclosed within parentheses.

6) What is the purpose of PYTHONPATH environment variable?

PYTHONPATH − It has a role similar to PATH. This variable tells the Python interpreter where to locate the module files imported into a program. It should include the Python source library directory and the directories containing Python source code. PYTHONPATH is sometimes preset by the Python installer

7) What are the tools that help to find bugs or perform static analysis?

PyChecker is a static analysis tool that detects the bugs in Python source code and warns about the style and complexity of the bug. Pylint is another tool that verifies whether the module meets the coding standard.

8) 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.

9) 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.

10) What is pass in Python?

Pass means, no-operation Python statement, or in other words it is a place holder in compound statement, where there should be a blank left and nothing has to be written there.

11) In Python what is slicing?

A mechanism to select a range of items from sequence types like list, tuple, strings etc. is known as slicing.

12) Explain Inheritance in Python with an example.

Inheritance allows One class to gain all the members (say attributes and methods) of another class. Inheritance provides code reusability, makes it easier to create and maintain an application. The class from which we are inheriting is called super-class and the class that is inherited is called a derived / child class.

They are different types of inheritance supported by Python:

Single Inheritance – where a derived class acquires the members of a single super class.

Multi-level inheritance – a derived class d1 in inherited from base class base1, and d2 are inherited from base2.

Hierarchical inheritance – from one base class you can inherit any number of child classes

Multiple inheritances – a derived class is inherited from more than one base class.

13) How can you copy an object in Python?

To copy an object in Python, you can try copy.copy () or copy.deepcopy() for the general case. You cannot copy all objects but most of them.

14) What is a negative index in Python?

Python sequences can be index in positive and negative numbers. For positive index, 0 is the first index, 1 is the second index and so forth. For negative index, (-1) is the last index and (-2) is the second last index and so forth.

15) What is a negative index in Python?

Python sequences can be index in positive and negative numbers. For positive index, 0 is the first index, 1 is the second index and so forth. For negative index, (-1) is the last index and (-2) is the second last index and so forth.

16) What is module and package in Python?

In Python, module is the way to structure program. Each Python program file is a module, which imports other modules like objects and attributes. The folder of Python program is a package of modules. A package can have modules or subfolders.

17) Mention what are the rules for local and global variables in Python?

Local variables: If a variable is assigned a new value anywhere within the function’s body, it’s assumed to be local.

Global variables: Those variables that are only referenced inside a function are implicitly global.

18) How will you get all the values from the dictionary?

Using dictionary.values() function, we can get all the values from the dictionary object.

19) Explain how to delete a file in Python?

By using a command os.remove (filename) or os.unlink(filename)

20) Mention five benefits of using Python?

i)Python comprises of a huge standard library for most Internet platforms like Email, HTML, etc.

ii)Python does not require explicit memory management as the interpreter itself allocates the memory to new variables and free them automatically

iii)Provide easy readability due to use of square brackets

iv)Easy-to-learn for beginners

v)Having the built-in data types saves programming time and effort from declaring variables