How do you create an instance of a class named 'Dog' in Python?
Dog = new()```
create Dog()```
my_dog = Dog()```
Dog.new()```
What will the following code snippet print?
d = {} d.setdefault('a', []).append(1) print(d['a'])
[1]
[]
1
KeyError: 'a'
What does the Counter class from the collections module do?
Counter
collections
Stores key-value pairs in the order of insertion.
Creates dictionaries with a default value for missing keys.
Implements a last-in, first-out (LIFO) data structure.
Counts the occurrences of elements in an iterable.
What is the purpose of the 'init.py' file in a Python package?
Defines the package's main function
Marks the directory as a Python package
Stores the package's documentation
Contains unit tests for the package
Consider the function definition: def my_func(a, b=5, *args, **kwargs): .... What does *args achieve?
def my_func(a, b=5, *args, **kwargs): ...
*args
It enforces that the function must be called with at least two arguments.
It defines a variable number of default arguments.
It collects any number of keyword arguments into a dictionary.
It collects any number of positional arguments into a tuple.
What differentiates a deque from a regular Python list?
deque
Deques are optimized for appending and popping elements from both ends, while lists are optimized for operations at the end.
Deques can only store integers, while lists can store any data type.
Deques are immutable, while lists are mutable.
Deques are thread-safe, while lists are not.
How do you create a custom exception class in Python?
By using the define_exception() keyword.
define_exception()
By defining a new class that inherits from the BaseException class or one of its subclasses.
BaseException
By using the custom_exception() function.
custom_exception()
By creating a new instance of the Exception class.
Exception
What does polymorphism allow objects of different classes to do in Python?
Have different data types for the same variable name
Respond to the same method call in their own specific way
Access private members of each other
Instantiate multiple times with different initial values
What does the following code snippet print?
def outer_func(x): def inner_func(y): return x + y return inner_func my_func = outer_func(5) print(my_func(3))
15
Error
5
8
What is the purpose of the 'r' prefix in a regular expression pattern?
It performs a greedy match.
It makes the pattern case-insensitive.
It enables multiline matching.
It treats the pattern as a raw string, ignoring escape sequences.