Interview Questions for Python

About Python

Python is a powerful multi-purpose programming language created by Guido van Rossum. It has simple easy-to-use syntax, making it the perfect language for someone trying to learn computer programming for the first time. Python is the most sought-after skill in programming domain. In this Python Interview Questions blog, I will introduce you to the most frequently asked questions in Python interviews. Our Python Interview Questions is the one-stop resource from where you can boost your interview preparation.

Python Interview Questions and Answers

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

• It is so easy to understand and easy syntax.
• Python has a scope in automation, data science, data analysis etc.
• Python provides less complexity in writing the code as compared to other languages like java, C#.

Python has a large library bank.  

What type of language is python? programming or scripting?

Python is capable of scripting, but in general sense, it is considered as a general-purpose programming language. To know more about Scripting, you can refer to the Python Scripting Tutorial.

What is PEP 8?

PEP 8 is the style guide to follow the coding practice to write the consistently understandable code.

What is namespace in Python?

A namespace is a naming system used to make sure that names are unique to avoid naming conflicts.

What is pickling and unpickling?

Is short pickling is converting python object into byte stream and un pickling is the reverse of pickling, pickle is the module in python which helps to do this job. And even we can use two methods is dumps and loads for that.

How Python is interpreted?

There is concept of compiler and interpreter but programming language codes are not machine level code so first python language code will be converted into machine code like byte code and then it will be interpreted if any fall happens in terms of error then the code will throw an error difference between interpreter and compiler is compiler compile full set of code even the code has some error and all the errors will be thrown in logs whereas interpreters stop interpreting code as soon as any error occurs.

What is PYTHONPATH?

 It is an environment variable which is used when a module is imported. Whenever a module is imported, PYTHONPATH is also looked up to check for the presence of the imported modules in various directories. The interpreter uses it to determine which module to load.

What are Python decorators?

Before understanding decorator we should understand function completely in python that’s is we can pass function as parameters, function can return and function, we can write nested function in python and  most important functions are same as object in python, so decorators are the tool which allows the programmer to change the behavior  of existing functions.

What are local variables and global variables in Python?

Global Variables:

Variables declared outside a function or in global space are called global variables. These variables can be accessed by any function in the program.

Local Variables:

Any variable declared inside a function is known as a local variable. This variable is present in the local space and not in the global space.

Example:

1: a=2

2: def add ():

3: b=3

4: c=a+b

5: print(c)

6: add ()

Output: 5

When you try to access the local variable outside the function add (), it will throw an error.

What is the difference between list and tuple?

The one main difference between list and tuple is enough to understand that list are mutable and tuples are immutable.

What is the meaning of immutable?

The data type which are declared once and cannot be modified those are mutable and which data types are provide the feature to update any point of time are comes under mutable data types and this is only the concepts of immutability.  

Is python case sensitive?

 Yes. Python is a case sensitive language.

How are arguments passed by value or by reference?

Python arguments are neither pass by value not pass by reference. Python is object centered language and everything in python is an object. So the python treatment with any data types are on the basis of assignment and its depends on the name.

What are the built-in type does python provides?

There so many built-in types are there in python like. Ex: None, long, int, str, float, long, list tuple, set, dict, range, x range and etc.

What is lambda in Python?

Lambda in python provides the way of writing the expression which returns the function object and then that function object can be called as function to execute the expression.

What are python integrators?

 Integrators are objects which can be traversed though or iterated upon. 

Why lambda forms in python does not have statements?

Lambda cannot contain the statements inside because the syntactic structure of the python cannot handle the nested statements in an expression because lambda has two part separated by “:” one is argument passing and another is for executions of expressions.

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.

What is passing in Python?

Pass is keyword in python which is used when statement is required but not executions are required so we can use pass key word, pass key word is mostly used with class and functions, function if not code need to write in that and class when no methods are required to write in that class.

What is unit test in Python?

Unit testing in python is as same as in other programming languages, testing of the smallest unit of the code is called unit testing and the smallest unit of the code is nothing but functions. We can use pyunit frame works to write the unit test.

What are the generators in python?

 Functions that return an iterable set of items are called generators.

What is the usage of help () and dir () function in Python?

Help () and dir () both functions are accessible from the Python interpreter and used for viewing a consolidated dump of built-in functions.

1. Help () function: The help () function is used to display the documentation string and also facilitates you to see the help related to modules, keywords, attributes, etc.
2. Dir () function: The dir () function is used to display the defined symbols.

In Python what is slicing?

All the data types which are sequence provided one feature that is slicing as by the name it is clear that slice something and in python we have slicing operator “:”

And by using “:” operator we can get the slice from any sequence. For example we Have list like

What is docstring in Python?

Doc string is nothing but a way of documentations for class, function and different modules in python.

What does Len () do?

It is used to determine the length of a string, a list, an array, etc.

Example:

1. Stg= ‘ AB CD’

Len ( stg )

How can you copy an object in Python?

There are two types of copy we can do of an object:

• Deep copy
• Shallow copy

To make the copy of an object we use copy module in python.

There are two method copy and deep Copy, copy function do shallow copy and deep Copy function do deep copy.

What is the difference between the shallow copy and deep copy in python?

As we know we have two methods to do copy of an objects when we do shallow copy the we copy an object and both main object and shadow object refers the same data so if any change will reflects where deep copy creates the individual copy of shadow object and change in shadow object does not reflect to the main object.

Define encapsulation in Python?

Encapsulation means binding the code and the data together. A Python class in an example of encapsulation.

How you can convert a number to a string?

Converting any data type into other data type is known as type conversion and in python we can convert data type by wrapping with class name.

For example: a = 10 and for converting b = Str (a)

What is module and package in Python?

Modules are nothing a code which is written for a specific purpose, it can be a class or functions. And we can design different useful modules in a python package that can be used by importing the package itself.

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

By default writing a variable outside functions and class are global variable and the variable inside function body or in class body are local variable of those components. If we want to use global variable in function then we have to explicitly mention variable with global key word.

Mention the use of // operator in Python?

Answer: The division value in which if output is quotient then digits after decimal places are removed. But if one value is negative then output will be floored means rounded away from zero.

Examples: 9//2 = 4 and 9.0//2.0 = 4.0, -11//3 = -4, -11.0//3 = -4.0

Does python make use of access specifiers?

Python does not deprive access to an instance variable or function. Python lays down the concept of prefixing the name of the variable, function or method with a single or double underscore to imitate the behavior of protected and private access specifiers.

Explain what are Flask & its benefits?

Flask is a python framework which helps us to easily work on rest API backend development and even it is used to do the web development.

Flask provides the configuration capability by creating the application instance and a lot more routing related stuffs can be done easily by using flask annotations.

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

Flask is a micro framework and used for small applications pyramid and Django are large framework and used for large applications pyramid provides the flexibility to use any of the tool and Django also do the same and even Django provides the Its own ORM also.

Is python numpy better than lists?

We use python numpy array instead of a list because of the below three reasons:

1. Less Memory
2. Fast

Convenient

How python manage memory?

Python always stores the objects the private heap of the program and all the objects will located there python maintains the immutability concepts with many data types to use the memory in optimized way.

Python uses its own garbage collector to clear the unreferenced data objects.

Which one of these is floor division?

a)       /

b)      //

c)       %

d)      None of the mentioned

Answer: b) //

How can you share variables across modules?

Sharing the members in between the modules are required to keep the members in any python file and we can import the python file itself to use those.

What are generators in Python?

There are lots of efforts are required to create integrators in python so we can simply use generators functions to create the integrators. We can write the function with yield instead of return keyword to return multiple values in python.

What is the maximum possible length of Identifier?

a)31 characters
b)63 characters
c)79 characters
d) None of the above

Answer: d) None of the above