Sorted()

Definition

The sorted() function in Python is a built-in function that returns a new sorted list from the elements of any iterable (such as a list, tuple, or string). It allows you to sort the elements in ascending order by default, or in descending order if specified. The sorted() function is a powerful tool for organizing and manipulating data in Python.

5 Must Know Facts For Your Next Test

1. The sorted() function returns a new sorted list, leaving the original iterable unchanged.
2. You can pass a reverse=True argument to the sorted() function to sort the elements in descending order.
3. The sorted() function can be used with any iterable, including lists, tuples, strings, and even sets and dictionaries.
4. The sorted() function can be combined with other Python constructs, such as list comprehension, to create powerful data manipulation techniques.
5. The sorted() function allows you to pass a key function to customize the sorting order, such as sorting by the length of the elements or by a specific attribute of each element.

Review Questions

• How can the sorted() function be used to sort a list of tuples based on the second element of each tuple?
  • To sort a list of tuples based on the second element of each tuple, you can pass a key function to the sorted() function. The key function should return the second element of each tuple, which will be used as the basis for sorting. For example, if you have a list of tuples [(1, 3), (2, 1), (3, 2)], you can sort it using sorted(list_of_tuples, key=lambda x: x[1]) to get the sorted list [(2, 1), (3, 2), (1, 3)].
• Explain how the sorted() function can be used in conjunction with a dictionary to sort the dictionary by its values.
  • To sort a dictionary by its values, you can use the sorted() function in combination with the items() method of the dictionary. The items() method returns a list of (key, value) tuples, which can then be passed to the sorted() function. By specifying a key function that returns the second element of each tuple (the value), the sorted() function will sort the list of tuples based on the dictionary values, and you can then create a new dictionary from the sorted list of tuples.
• How can you use the sorted() function to sort a list of strings in reverse alphabetical order?
  • To sort a list of strings in reverse alphabetical order using the sorted() function, you can pass the reverse=True argument. For example, if you have a list of strings ['apple', 'banana', 'cherry', 'date'], you can use sorted(list_of_strings, reverse=True) to get the sorted list ['date', 'cherry', 'banana', 'apple']. The sorted() function will sort the list in descending alphabetical order, effectively giving you the reverse alphabetical order.

Related terms

List Comprehension: A concise way to create a new list by applying an expression to each item in an iterable, such as a list, tuple, or string.

Reverse(): A built-in list method that reverses the order of the elements in a list.

Key Function: A function passed to the sorted() function that allows you to customize the sorting order by specifying a key to extract from each element.