Python Developer

  Home  Web Development  Python Developer


“Python Developer related Frequently Asked Questions by expert members with professional career as Python Developer. These list of interview questions and answers will help you strengthen your technical skills, prepare for the new job interview and quickly revise your concepts”



77 Python Developer Questions And Answers

41⟩ Explain me what Is A Built-In Function That Python Uses To Iterate Over A Number Sequence?

range() generates a list of numbers, which is used to iterate over for loops.

for i in range(5):

print(i)

The range() function accompanies two sets of parameters.

☛ range(stop)

☛ stop: It is the no. of integers to generate and starts from zero. eg. range(3) == [0, 1, 2].

☛ range([start], stop[, step])

☛ start: It is the starting no. of the sequence.

☛ stop: It specifies the upper limit of the sequence.

☛ step: It is the incrementing factor for generating the sequence.

☛ Points to note:

☛ Only integer arguments are allowed.

☛ Parameters can be positive or negative.

☛ The <range()> function in Python starts from the zeroth index.

 190 views

42⟩ Do you know how memory is managed in Python?

☛ Python memory is managed by Python private heap space. All Python objects and data structures are located in a private heap. The programmer does not have an access to this private heap and interpreter takes care of this Python private heap.

☛ The allocation of Python heap space for Python objects is done by Python memory manager. The core API gives access to some tools for the programmer to code.

☛ Python also have an inbuilt garbage collector, which recycle all the unused memory and frees the memory and makes it available to the heap space.

 150 views

44⟩ Explain me database connection in Python Flask?

Flask supports database powered application (RDBS). Such system requires creating a schema, which requires piping the shema.sql file into a sqlite3 command. So you need to install sqlite3 command in order to create or initiate the database in Flask.

Flask allows to request database in three ways

before_request() : They are called before a request and pass no arguments

after_request() : They are called after a request and pass the response that will be sent to the client

teardown_request(): They are called in situation when exception is raised, and response are not guaranteed. They are called after the response been constructed. They are not allowed to modify the request, and their values are ignored.

 125 views

45⟩ Explain me what are the key features of Python?

These are the few key features of Python:

☛ Python is an interpreted language. That means that, unlike languages like C and its variants, Python does not need to be compiled before it is run. Other interpreted languages include PHP and Ruby.

☛ Python is dynamically typed, this means that you don’t need to state the types of variables when you declare them or anything like that. You can do things like x=111 and then x="I'm a string" without error

☛ Python is well suited to object orientated programming in that it allows the definition of classes along with composition and inheritance. Python does not have access specifiers (like C++’s public, private), the justification for this point is given as “we are all adults here”

☛ In Python, functions are first-class objects. This means that they can be assigned to variables, returned from other functions and passed into functions. Classes are also first class objects

☛ Writing Python code is quick but running it is often slower than compiled languages. Fortunately,Python allows the inclusion of C based extensions so bottlenecks can be optimized away and often are. The numpy package is a good example of this, it’s really quite quick because a lot of the number crunching it does isn’t actually done by Python

☛ Python finds use in many spheres – web applications, automation, scientific modelling, big data applications and many more. It’s also often used as “glue” code to get other languages and components to play nice.

 127 views

48⟩ Tell me why And When Do You Use Generators In Python?

A generator in Python is a function which returns an iterable object. We can iterate on the generator object using the <yield> keyword. But we can only do that once because their values don’t persist in memory, they get the values on the fly.

Generators give us the ability to hold the execution of a function or a step as long as we want to keep it. However, here are a few examples where it is beneficial to use generators.

☛ We can replace loops with generators for efficiently calculating results involving large data sets.

☛ Generators are useful when we don’t want all the results and wish to hold back for some time.

☛ Instead of using a callback function, we can replace it with a generator. We can write a loop inside the function doing the same thing as the callback and turns it into a generator.

 148 views

49⟩ Explain me 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.

 120 views

51⟩ How to minimize the Memcached server outages in your Python Development?

☛ • When one instance fails, several of them goes down, this will put larger load on the database server when lost data is reloaded as client make a request. To avoid this, if your code has been written to minimize cache stampedes then it will leave a minimal impact

☛ • Another way is to bring up an instance of Memcached on a new machine using the lost machines IP address

☛ • Code is another option to minimize server outages as it gives you the liberty to change the Memcached server list with minimal work

☛ • Setting timeout value is another option that some Memcached clients implement for Memcached server outage. When your Memcached server goes down, the client will keep trying to send a request till the time-out limit is reached

 131 views

52⟩ Tell us 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.

 140 views

56⟩ Tell me what Do You Think Is The Output Of The Following Code Fragment? Is There Any Error In The Code?

list = ['a', 'b', 'c', 'd', 'e']

print (list[10:])

The result of the above lines of code is []. There won’t be any error like an IndexError.

You should know that trying to fetch a member from the list using an index that exceeds the member count (for example, attempting to access list[10] as given in the question) would yield an IndexError. By the way, retrieving only a slice at an opening index that surpasses the no. of items in the list won’t result in an IndexError. It will just return an empty list.

 203 views

58⟩ Do you know how is memory managed in Python?

☛ Python memory is managed by Python private heap space. All Python objects and data structures are located in a private heap. The programmer does not have an access to this private heap and interpreter takes care of this Python private heap.

☛ The allocation of Python heap space for Python objects is done by Python memory manager. The core API gives access to some tools for the programmer to code.

☛ Python also have an inbuilt garbage collector, which recycle all the unused memory and frees the memory and makes it available to the heap space.

 152 views

59⟩ Tell me how Does Python Handle The Memory Management?

☛ Python uses private heaps to maintain its memory. So the heap holds all the Python objects and the data structures. This area is only accessible to the Python interpreter; programmers can’t use it.

☛ And it’s the Python memory manager that handles the Private heap. It does the required allocation of the heap for Python objects.

☛ Python employs a built-in garbage collector, which salvages all the unused memory and offloads it to the heap space.

 147 views