Examples of Interview Questions for the Position of "Junior Python Developer"
Here is a list of possible questions and brief answers for the interview:
What is Python, and what makes it special?
Python is a versatile and easy-to-learn programming language known for its clear and readable syntax. It is used for web development, scripting, data analysis, and more.
What are the differences between lists and tuples in Python?
Lists: Mutable, used for storing homogeneous data.
Tuples: Immutable, used for storing heterogeneous data.
What is a dictionary in Python?
A dictionary is a data structure that stores key-value pairs, allowing fast access to values using the associated keys.
Explain what "indentation" means in Python.
"Indentation" represents the space or tab used to define code blocks. It is essential in Python to mark the logical structure of the program.
How do we handle exceptions in Python?
We use the
try and
except blocks to catch and handle exceptions, preventing the program from crashing unexpectedly.
What is the difference between append() and extend() in a list?
append() adds an element to the end of the list, while
extend() adds elements from another list to the end of the first list.
How can you import modules in Python?
We use the
import statement to bring functionalities from other modules into our program.
What is virtualenv and why is it useful?
Virtualenv is a tool that allows creating isolated development environments to manage project dependencies, avoiding conflicts between packages.
How can you iterate over two or more lists simultaneously?
We use the
zip() function to iterate over multiple lists at the same time, creating pairs of corresponding elements.
How can you automatically open and close a file in Python?
Use the
with block to open and close a file automatically, ensuring that resources are managed correctly
(see more details in [
Lesson 20]).
What is a magic method (dunder method) in Python?
Magic methods are special methods with double underscores (
__) at the beginning and end,
used to define special behaviors in a class, such as
__init__ for the constructor.
How can we create a function in Python?
We use the
def keyword to define a function and specify the function name, parameters, and associated code.
Difference between shallow copy and deep copy in Python?
Shallow copy only copies the references to the objects, while
deep copy creates independent copies of the
objects and all embedded objects.
Explain what the split() method does for strings?
The
split() method divides a string based on a specified separator and returns a list of the resulting parts.
For example:
sentence = "Python is popular"
words = sentence.split()
print(words) # Displays: ['Python', 'is', 'popular']
How can we comment code in Python?
We can add comments using
# for single-line comments and triple quotes
(''' or """) for multi-line comments.
What is recursion and how does it work in Python?
Recursion is a technique where a function calls itself to solve a problem.
It is important to have a base case to avoid infinite loops.
A common example of recursion is calculating the factorial of a number. To get the factorial of a number
n,
we can use the formula
n! = n * (n-1)!, where
(n-1)! is the factorial of the previous number. Thus, the recursive function will
calculate the factorial of the current number by calling itself for the previous number until it reaches the base
case when
n becomes
1.
How can you handle modules with functions of the same name from different packages?
Use aliases to import modules with the same name from different packages, allowing you to use the module names without ambiguity.
How can you reverse a string in Python?
Use the
slicing technique (
[::-1]) to reverse a string.
What is List Comprehension and how does it work?
List Comprehension is a concise syntax for creating lists using a single line of code.
It is used to iterate over a sequence and apply an expression to each element.
Consider the example below:
numbers = [1, 2, 3, 4, 5]
squares = [number ** 2 for number in numbers]
print(squares) # Displays: [1, 4, 9, 16, 25]
How do you handle multiple exceptions in a single except block?
You can use a tuple to specify multiple exception types in a single except block,
or you can use multiple separate except blocks for each exception type. For example:
try:
# Code that may generate exceptions
number = int(input("Enter a number: "))
result = 10 / number
except (ValueError, ZeroDivisionError):
print("An error occurred in data entry or division by zero.")
except Exception as e:
print("An unexpected error occurred:", str(e))
else:
print("The result is:", result)
How can you iterate over the elements of a dictionary in Python?
Use "
for key, value in dictionary.items():" to iterate over key-value pairs in a dictionary.
What is a decorator in Python and what is it used for?
A decorator is a function that modifies the behavior of another function or method. They are
usually used to add additional functionalities transparently.
How do you manage external dependencies in a Python project?
We use a tool like pip to install and manage the packages and modules needed for the project.
How can you create a generator in Python and what is it used for?
A generator is created using functions with
yield instead of
return. They are used to generate
values efficiently in terms of memory, avoiding storing all data in memory.
What is the difference between a class and an object in Python?
A class is a blueprint for creating objects, while an object is a specific instance of a class.
How can you read and write data to a text file in Python?
Use the
open() function (or with
with) to open a file and then the
read() and
write() methods to read and write data.
Explain what the * operator does when used with a list in Python.
The * operator is used to multiply a list by an integer, generating a new list
that contains the initial elements repeated the specified number of times.
What is string concatenation in Python?
String concatenation involves combining two or more strings to form a longer string.
This can be done using the + operator or the
str.join() method.
How can you read and write data to a CSV file in Python?
Use the
csv module to read and write data to a
CSV file, using the
csv.reader() and
csv.writer() functions.
How can you check if an element exists in a dictionary in Python?
Use "
if key in dictionary:" to check if a key exists in a dictionary.
Explain the difference between lambda functions and functions defined with def in Python.
Lambda functions are anonymous functions and can be used to create simple functions in a single line,
while functions defined with
def can have names and are used for more complex functionality.
What is a finally clause and how is it used in try-except exception handling?
The
finally clause is used to specify a block of code that will be executed regardless of whether an
exception occurred or not in a
try block. For example, to release resources.
What is the collections module and how is it used in Python?
The
collections module contains specialized classes to manage and store collections of data, such as
dictionaries with default values or queues.
What is the json module in Python and how is it used to work with JSON data?
The
json module provides functions to serialize and deserialize
JSON (JavaScript Object Notation) data,
allowing easy manipulation of structured data.
How can you check if two objects are identical (have the same reference) in Python?
Use the is operator to check if two objects have the same reference in memory.
How can you use the random module to generate random numbers in Python?
Use functions such as
random.random() to generate real numbers between 0 and 1 or
random.randint(a, b)
to generate integers between a and b.
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