Frequently asked Python interview questions

Python Interview Questions

Q: What is Python?
Ans:

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.

Python is a programming language with objects, modules, threads, exceptions and automatic memory management.

Q: What are the benefits of Python ?
Ans:

• Simple to learn, portable extensible, dynamic-typed open source
• Supports object-oriented programming as you can define classes along with composition and inheritance.
• Python has a number of uses, including web-based applications, test automation, data mining, big data analytics, machine learning, and more.
• Python consists of a large standard library for most Internet channels such as email, HTML, etc.
• Python needs no specific memory management as the interpreter himself allocates and automatically clears the memory for new variables

Q: What is Python 3?
Ans:

• Python 3 is the latest Python version. Python 2 is history, Python 3 is the future
• Python 3 embraces modern techniques such as AI, machine learning and data science.
• Python 3 is supported by a large Python developer community. It's quick to get help.
• Python 3 has elegantly changed its architecture so that fewer lines of code are required to perform an action.
• Python 3 offers a versatile toolkit and libraries

Q: Why is Python so Popular?
Ans:

Here are prime reasons for Python popularity:

• Supports modern techniques such as AI, machine learning and data science.
• In-demand : Python has a large developer community. It's quick to get help. Python developers are frequently employed by a host of companies around the world.
• Python is the new Excel : The reason Python is taught at business school is that Python is like Excel on steroids. Python's financial analysts, data scientists, and data-driven marketers can leverage Python's power to crack big data.
• Simplicity : It's easy to understand the syntax (or "grammar" of Python). It's easier to learn Python language.
• Flexibility : Offers Powerful toolkit and libraries. Mixable with other languages

Q: What is pip in Python ?
Ans:

Pip is the standard Python package manager. This helps you to download and manage external modules that are not part of the standard Python library.

Package management is so critical that Python 3 has been included with the Python installer since version 3.4.

Q: What is PEP ?
Ans:

Python coding standard, a set of coding recommendations. It guides to deliver more readable Python code.

Q: What are data type in python?
Ans:

Mutable built-in types

• List
• Sets
• Dictionaries

Immutable built-in types

• Strings
• Tuples
• Numbers

Q: What is the difference between list and tuple?
Ans:

The difference between list and tuple is that list is mutable while tuple is not. Tuple can be hashed for e.g as a key for dictionaries.

Q: How are arguments passed by value or by reference?
Ans:

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

Q: What is Dict and List comprehensions are?
Ans:

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

Q: What is namespace in Python?
Ans:

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.

Q: What is lambda in Python?
Ans:

It is a single expression anonymous function often used as inline function. A lambda form in python does not have statements as it is used to make new function object and then return them at runtime.

Instead of def keywords, we use the ' lambda method. ' They use a lambda keyword. There may be a number of arguments for Lambda functions, but it can only have a one statement.

Q: What is pass in Python?
Ans:

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.

Q: What is the difference between Xrange and range?
Ans:

Xrange returns the xrange object while range returns the list, and uses the same memory and no matter what the range size is.

Q: What is module and package in Python?
Ans:

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.

The modules are independent,.py extension Python scripts which can be reused using the import clause in other Python codes or scripts. e.g. import mymodule

Q: what are the rules for local and global variables in Python?
Ans:

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. 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.

Q: what is Flask and its benefits?
Ans:

Flask is a web micro framework for Python based on "Werkzeug, Jinja 2 and good intentions" BSD licensed. Werkzeug and jingja are two of its dependencies. Flask is part of the micro-framework. Which means it will have little to no dependencies on external libraries. It makes the framework light while there is little dependency to update and less security bugs