NPTEL Data Science Using Python – Week 4: Assignment 4 Answers

NPTEL Data Science Using Python – Week 4: Assignment 4 Answers

1. Which method would you use to check if a string contains only digits?

• isnumeric()
• isdigit()
• isdecimal()
• isnumber()

2. Which of the following are true about strings in Python?

• Answer: Strings are immutable. Strings can be created using single, double, or triple quotes. You can access characters in a string using positive or negative indices. Strings support the multiplication operator for repetition.
• Strings are immutable.
• Strings can be created using single, double, or triple quotes.
• You can access characters in a string using positive or negative indices.
• Strings support the multiplication operator for repetition.

3. Which operations can be performed with strings in Python?

• Concatenation
• Multiplication
• Division
• Slicing

4. Python strings are __, meaning that once they are created, they cannot be altered.

• Answer: Immutable

5. To check if a character or substring exists within another string, the __ operator is used.

• Answer: in

6. Which statements about lists in Python are correct?

• Lists are mutable.
• Lists can contain elements of different types.
• Lists contain elements from the same type only.
• Lists cannot contain duplicate elements.

7. Given the list data = [10, 20, 30, 20, 10, 50, 60, 40, 80, 50, 40], which of the following code snippets would correctly remove all duplicate items and keep only unique items in the list?

• list(set(data))
• data.remove(duplicates)
• data.unique()
• unique(data)

8. Select all the correct statements about the function text_processor based on its description and functionality:

• The function returns all words from the input.
• The function returns the total number of words in the input.
• The function returns a list of the longest words found in the input string.
• The function counts and returns the number of unique words in the input.

9. What does the function text_processor return when called with the string “hello world hello Python”?

• (['Python'], 4)
• (['hello', 'Python'], 3)
• (['hello'], 2)
• (['Python'], 3)

10. What does the following tuple slicing operation return: (1, 2, 3, 4, 5)[1:3]?

• (1, 2)
• (2, 3)
• (3, 4)
• (2, 3, 4)

11. Which operation is not possible with tuples in Python?

• Accessing elements by index
• Concatenating with another tuple
• Modifying an element
• Using the in operator to check membership

12. What is the output of set([1, 2, 2, 3, 4, 1, 5])?

• Answer: {1, 2, 3, 4, 5}
• [1, 2, 3, 4, 5]
• {1, 2, 3, 4, 5}
• (1, 2, 3, 4, 5)
• None of the above

13. Dictionaries in Python are collections of key-value pairs where keys must be __.

• Answer: Immutable

14. What will be the result of inventory['001']['price']?

• Answer: 29.95
• 'Python Programming'
• 'John Doe'
• 29.95
• True

15. Which operations are valid to modify the book inventory based on the provided dictionary data?

• Adding a new book: inventory['003'] = {'title': 'Data Science Fundamentals', 'author': 'Laura Brown', 'price': 40.00, 'available': True}
• Removing a book from the inventory: del inventory['002']
• Changing the author of a book: inventory['001']['author'] = 'Johnathan Doe'
• Checking if a book is available using: inventory['001']['in_stock']