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
inoperator 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'29.95True
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']