index error in python

1# main.py
2import datetime
3
4from gw_utility.book import Book
5from gw_utility.logging import Logging
6
7
8def main():
9    try:
10        # Create list and populate with Books.
11        books = list()
12        books.append(Book("Shadow of a Dark Queen", "Raymond E. Feist", 497, datetime.date(1994, 1, 1)))
13        books.append(Book("Rise of a Merchant Prince", "Raymond E. Feist", 479, datetime.date(1995, 5, 1)))
14        books.append(Book("Rage of a Demon King", "Raymond E. Feist", 436, datetime.date(1997, 4, 1)))
15
16        # Output Books in list, with and without index.
17        Logging.line_separator('Books')
18        log_list(books)
19        Logging.line_separator('Books w/ index')
20        log_list(books, True)
21        # Output list element outside bounds.
22        Logging.line_separator('books[len(books)]')
23        Logging.log(f'books[{len(books)}]: {books[len(books)]}')
24    except IndexError as error:
25        # Output expected IndexErrors.
26        Logging.log_exception(error)
27    except Exception as exception:
28        # Output unexpected Exceptions.
29        Logging.log_exception(exception, False)
30
31
32def log_list(collection, include_index=False):
33    """Logs the each element in collection to the console.
34
35    :param collection: Collection to be iterated and output.
36    :param include_index: Determines if index is also output.
37    :return: None
38    """
39    try:
40        # Iterate by converting to enumeration.
41        for index, item in enumerate(collection):
42            if include_index:
43                Logging.log(f'collection[{index}]: {item}')
44            else:
45                Logging.log(item)
46    except IndexError as error:
47        # Output expected IndexErrors.
48        Logging.log_exception(error)
49    except Exception as exception:
50        # Output unexpected Exceptions.
51        Logging.log_exception(exception, False)
52
53
54if __name__ == "__main__":
55    main()
56

1# IndexError comes because you are trying to get the item that don't exists 
2# it means if you ant to get the numbers
3
4numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9 10]
5length_of_numbers = len(numbers)
6
7printnumbers(length_of_numbers)		# raises IndexError because the len() 
8# function starts counting from 1 but the index sarts counting from 0