Mastering Data Structures

What is a list in Python and how is it different from a tuple?

• A list is defined with {}, while a tuple is defined with []

• A list is mutable and defined with [], while a tuple is immutable and defined with ().

• A list can only contain numbers, while a tuple can contain any data type.

• A list is immutable and defined with [], while a tuple is mutable and defined with ().

Explain the concept of a dictionary in Python. How is it structured?

• A dictionary in Python is a single key without a value.

• A dictionary in Python is structured as [key, value].

• A dictionary in Python is a collection of key-value pairs, structured as {key: value}.

• A dictionary in Python is a list of items.

What are sets in Python and what are their main characteristics?

• Sets in Python can contain mutable elements like lists.

• Sets in Python are ordered collections of duplicate elements.

• Sets in Python are unordered collections of unique elements.

• Sets in Python are a type of dictionary with key-value pairs.

How do you add an element to a list in Python?

• list.insert(element) is the method to add an element to a list.

• Use list.add(element) to insert an element into a list.

• Use list.push(element) to append an element to a list.

• Use list.append(element) to add an element to a list.

What is the purpose of the 'pop' method in a list?

• The 'pop' method checks if an item exists in the list.

• The 'pop' method adds an item to the end of a list.

• The 'pop' method sorts the items in the list.

• The 'pop' method is used to remove and return an item from a list.

Describe how a stack data structure works and provide an example in Python.

• In Python, a stack is implemented using a dictionary instead of a list.

• A stack can only store integers and not other data types.

• A queue data structure allows insertion and deletion from both ends.

• Example in Python: class Stack: def __init__(self): self.items = [] def push(self, item): self.items.append(item) def pop(self): return self.items.pop() if not self.is_empty() else None def is_empty(self): return len(self.items) == 0 def peek(self): return self.items[-1] if not self.is_empty() else None stack = Stack() stack.push(1) stack.push(2) print(stack.pop()) # Output: 2

What is a queue and how can it be implemented in Python?

• A queue is a data structure that follows LIFO and can be implemented using 'list' or 'set'.

• A queue is a type of stack that can be implemented using 'array' or 'tuple'.

• A queue is a data structure that allows random access and can be implemented using 'dict' or 'frozenset'.

• A queue is a data structure that follows FIFO, and it can be implemented in Python using 'collections.deque' or 'queue.Queue'.

Explain the difference between shallow copy and deep copy in Python data structures.

• Shallow copy duplicates all objects, while deep copy only duplicates the top-level object.

• Shallow copy and deep copy are the same and can be used interchangeably.

• Shallow copy creates a new object with references to the original's objects; deep copy creates a new object with copies of the original's objects.

• Deep copy creates a new object with references to the original's objects, while shallow copy creates a new object with copies of the original's objects.

What are the advantages of using a linked list over an array?

• Slower search times

• Higher memory overhead

• Advantages of using a linked list over an array include dynamic size, efficient insertions and deletions, and better memory management.

• Fixed size allocation

How can you traverse a dictionary in Python?

• Use a while loop to traverse the dictionary.

• Convert the dictionary to a list before traversal.

• Access dictionary elements using their index.

• Use a for loop with dict.keys(), dict.values(), or dict.items() to traverse a dictionary.