w3resource

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

Python Lambda: Exercise-37 with Solution

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

Sample Solution:

Python Code :

def index_on_inner_list(list_data, index_no):
    result = sorted(list_data, key=lambda x: x[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)]

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 extract the nth element from a given list of tuples using lambda.
Next: Write a Python program to remove all elements from a given list present in another list using lambda.

What is the difficulty level of this exercise?

Test your Python skills with w3resource's quiz



Python: Tips of the Day

Python: Cache results with decorators

There is a great way to cache functions with decorators in Python. Caching will help save time and precious resources when there is an expensive function at hand.

Implementation is easy, just import lru_cache from functools library and decorate your function using @lru_cache.

from functools import lru_cache

@lru_cache(maxsize=None)
def fibo(a):
    if a <= 1:
        return a
    else:
        return fibo(a-1) + fibo(a-2)

for i in range(20):
    print(fibo(i), end="|")

print("\n\n", fibo.cache_info())

Output:

0|1|1|2|3|5|8|13|21|34|55|89|144|233|377|610|987|1597|2584|4181|

 CacheInfo(hits=36, misses=20, maxsize=None, currsize=20)