JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II PYTHON PROGRAMMING Previous Question Paper (August/ September - 2022 - R18)

List access methods in Python allow for retrieving, modifying, or traversing elements within a list. The primary methods include:

• Indexing: Accessing a single element using its position. Python uses zero-based indexing, where the first element is at index 0. Negative indexing allows access from the end of the list, where -1 refers to the last element.
• Slicing: Extracting a sub-list using the syntax list[start:stop:step]. This creates a new list containing elements from the start index up to, but not including, the stop index, with an optional step value.
• Iteration: Traversing the list using loops. The for loop is the most common way to access each element sequentially. Alternatively, enumerate() can be used to access both the index and the value simultaneously.
• Membership Testing: Using the in operator to check if a specific element exists within the list, returning a boolean value.
• List Methods for Access/Search: Methods like index() return the position of the first occurrence of a value, and count() returns the number of times a value appears in the list.

To calculate the factorial of a number using a function, one can use either an iterative approach or a recursive approach. Below is the iterative implementation:

def factorial(n):
    if n < 0:
        return "Factorial does not exist for negative numbers"
    result = 1
    for i in range(1, n + 1):
        result *= i
    return result

num = int(input("Enter a number: "))
print(f"The factorial of {num} is {factorial(num)}")