␡
- 5.1 Introduction
- 5.2 Lists
- 5.3 Tuples
- 5.4 Unpacking Sequences
- 5.5 Sequence Slicing
- 5.6 del Statement
- 5.7 Passing Lists to Functions
- 5.8 Sorting Lists
- 5.9 Searching Sequences
- 5.10 Other List Methods
- 5.11 Simulating Stacks with Lists
- 5.12 List Comprehensions
- 5.13 Generator Expressions
- 5.14 Filter, Map and Reduce
- 5.15 Other Sequence Processing Functions
- 5.16 Two-Dimensional Lists
- 5.17 Intro to Data Science: Simulation and Static Visualizations
- 5.18 Wrap-Up
This chapter is from the book
This chapter is from the book
This chapter is from the book
This chapter is from the book
5.8 Sorting Lists
Sorting enables you to arrange data either in ascending or descending order.
Sorting a List in Ascending Order
List method sort modifies a list to arrange its elements in ascending order:
In [1]: numbers = [10, 3, 7, 1, 9, 4, 2, 8, 5, 6] In [2]: numbers.sort() In [3]: numbers Out[3]: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Sorting a List in Descending Order
To sort a list in descending order, call list method sort with the optional keyword argument reverse- set to True (False is the default):
In [4]: numbers.sort(reverse=True) In [5]: numbers Out[5]: [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
Built-In Function sorted
Built-in function sorted returns a new list containing the sorted elements of its argument sequence—the original sequence is unmodified. The following code demonstrates function sorted for a list, a string and a tuple:
In [6]: numbers = [10, 3, 7, 1, 9, 4, 2, 8, 5, 6]
In [7]: ascending_numbers = sorted(numbers)
In [8]: ascending_numbers
Out[8]: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
In [9]: numbers
Out[9]: [10, 3, 7, 1, 9, 4, 2, 8, 5, 6]
In [10]: letters = 'fadgchjebi'
In [11]: ascending_letters = sorted(letters)
In [12]: ascending_letters
Out[12]: ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j']
In [13]: letters
Out[13]: 'fadgchjebi'
In [14]: colors = ('red', 'orange', 'yellow', 'green', 'blue')
In [15]: ascending_colors = sorted(colors)
In [16]: ascending_colors
Out[16]: ['blue', 'green', 'orange', 'red', 'yellow']
In [17]: colors
Out[17]: ('red', 'orange', 'yellow', 'green', 'blue')
Use the optional keyword argument reverse with the value True to sort the elements in descending order.