Ace Your Next Python Interview: 10 Essential Questions and Answers
If you are new to the blog then you may have noticed we talk about technical topics. I have discussed data structures and algorithms, which help if you did not pay attention to the fundamentals or basics when you first started learning to program. It can be extremely annoying to go back to the basics but these kinds of reviews will pay off if you have an interview approaching. Or let’s say you’re content with your job , side hustle or Start-Up, it never hurt to be prepared.
For today, we’re pivoting from where we left off in November, and will be talking more about Python interview prep.We will still focus on interview prep for those trying to break into the tech industry!
This blog will be about the fundamental knowledge and concepts to show off your Python knowledge!
Python Interview Questions
- What is a Python decorator ?
– Python Decorators: A tool that allows developers to change the behavior of a function or method. Decorators take a function or method as an input, modify it in some way, and then return the modified version. This modified version can then be used instead of the original function or method.Decorators can be used to add new features to existing functions or methods, or create entirely new ones. - What is _init_ in Python ?
– _init_ is a special method that runs automatically when a class creates an object (or instance). It is used to set up the attributes of the object when it is created. It allocate memory so that the object can be used and stored. - What is a lambda function in Python ?
-A lambda functionn is like any other function in Python, but it is unnamed and written in a single line of code. It can take multiple inputs, but only one expression. To write a lambda function, use the following syntax:
lambda parameter(s): expression
This statement will evaluate the expression and return results.
– For example, the lambda function:
X = lambda y:y + 4 takes a single parameter and return y+4.
Another Example
X = lambda y, z:y *z, takes two parameters y and z and returns their product. - Whats the difference between an iterable and an iterator in Python ?
– Iterables are objects that can contain other objects.A list is an example of an iterable because it can contain other items, like number and strings. An iterator is a way to go through the items in a list one by one. To do this, a special function called _iter_ and _next_ are defined. The _iter_ function returns the iterator object, while the _next_ returns the next item on the list. Iterables are important to understand because they will allow us to loop through the contents of a container. - What is a Python generator ?
– Python generators are special functions that create an iterator. This is like a list of values, but instead of loading the entire list in your computer’s memory, it breaks it up into chunks and returns it one piece at a time. This is useful when working with large datasets, as it doesn’t take up as much memory. - What is the difference between == and is in Python ?
– When we determine if two objects are equal, we look at the values of the objects. To determine if two objects are identical, we look at where the objects are located in memory. The double equal sign (==) checks to see if two values are the same, while the single equal sign (is) checks for identity, making sure that two strings are the same, even if there are differences like whitespaces.
– For example: Two lists might contain the same contents and therefore be equal, but they might not be located in the same spot memory, making them not identical. - What is the difference between str() and repr () in Python ?
– Str() and Repr() are both ways of getting a string representation of an object. Str() is meant to be easy for humans to read, so the string representation of the object’s data may look different from the actual data.
-It is usually used for creating output that people will read repr() is meant to be easy for computers to read, so the string representation of the object’s data is the same as the actual data. Usually used for debugging and development. - What is GIL ?
– A Global Interpreter Lock, or GIL is a way to make sure only one program can use python interpreter at a time. This helps keep Python programs from running into problems when two or more programs try to use the same information at the same time. - What is the difference between a shallow copy and a deep copy ?
– A shallow copy creates a new list that points to the same items as the source list.
– A deep copy creates new copies of the items in the source list and puts them in a new list. - What is the difference between serialization and pickling ?
– Serialization is a way of converting an object into a form that be saved and stored, like in a a file. Python has a special feature called ‘ pickling’ that does this for you. It takes the data of the object and compresses it into a sequence of bytes, which can be stored in a file.
– This helps prevent any data from being lost or corrupted if the system crashes. Pickling also makes it possible to transfer data between systems that use different file formats. The function in Python that does is called ‘pickle.dump()’ .
Summary
Interviews can be stressful but preparation can keep your mind at ease. After several rounds of interviews I can attest and say the better prepared the less pressure and stress you have to deal with. The fundamental concepts we covered today should give you a general understanding of the basics and being able to speak intelligently about them will help you make an impressive first impression.
References:
- Elements of programming Interviews
- Cracking The coding interview — Book
- https://www.geeksforgeeks.org/learn-data-structures-and-algorithms-dsa-tutorial/
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