Please note, this is a STATIC archive of website www.w3resource.com from 19 Jul 2022, cach3.com does not collect or store any user information, there is no "phishing" involved.
w3resource

Python: Sort a list of lists by a given index of the inner list

Python List: Exercise - 116 with Solution

Write a Python program to sort a list of lists by a given index of the inner list.

Sample Solution:

Python Code:

from operator import itemgetter
def index_on_inner_list(list_data, index_no):
    result = sorted(list_data, key=itemgetter(index_no))
    return result
students = [('Greyson Fulton', 98, 99), ('Brady Kent', 97, 96), ('Wyatt Knott', 91, 94), ('Beau Turnbull', 94, 98)] 
print ("Original list:")
print(students)
index_no = 0
print("\nSort the said list of lists by a given index","( Index = ",index_no,") of the inner list")
print(index_on_inner_list(students, index_no))
index_no = 2
print("\nSort the said list of lists by a given index","( Index = ",index_no,") of the inner list")
print(index_on_inner_list(students, index_no))

Sample Output: 

Original list:
[('Greyson Fulton', 98, 99), ('Brady Kent', 97, 96), ('Wyatt Knott', 91, 94), ('Beau Turnbull', 94, 98)]

Sort the said list of lists by a given index ( Index =  0 ) of the inner list
[('Beau Turnbull', 94, 98), ('Brady Kent', 97, 96), ('Greyson Fulton', 98, 99), ('Wyatt Knott', 91, 94)]

Sort the said list of lists by a given index ( Index =  2 ) of the inner list
[('Wyatt Knott', 91, 94), ('Brady Kent', 97, 96), ('Beau Turnbull', 94, 98), ('Greyson Fulton', 98, 99)]

Pictorial Presentation:

Python List: Sort a list of lists by a given index of the inner list.
Python List: Sort a list of lists by a given index of the inner list.

Flowchart:

Flowchart: Sort a list of lists by a given index of the inner list.

Visualize Python code execution:

The following tool visualize what the computer is doing step-by-step as it executes the said program:


Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a Python program to check if the elements of a given list are unique or not.
Next: Write a Python program to remove all elements from a given list present in another list.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Python: Tips of the Day

Find current directory and file's directory:

To get the full path to the directory a Python file is contained in, write this in that file:

import os 
dir_path = os.path.dirname(os.path.realpath(__file__))

(Note that the incantation above won't work if you've already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working directory and is not changed by an os.chdir() call.)

To get the current working directory use

import os
cwd = os.getcwd()

Documentation references for the modules, constants and functions used above:

  • The os and os.path modules.
  • The __file__ constant
  • os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")
  • os.path.dirname(path) (returns "the directory name of pathname path")
  • os.getcwd() (returns "a string representing the current working directory")
  • os.chdir(path) ("change the current working directory to path")

Ref: https://bit.ly/3fy0R6m