Sort by last name
Input
sort_names_by_last(['Ada Lovelace', 'Alan Turing', 'Grace Hopper'])
Output
['Grace Hopper', 'Ada Lovelace', 'Alan Turing']
Last names: Hopper, Lovelace, Turing -> Hopper, Lovelace, Turing
Full lesson preview
Sort names by last name using a lambda key
Use sorted with a lambda key that extracts the last name to sort a list of full names.
Python practice15 minFunctions as Objects (Lambda, Map/Filter)IntermediateLast updated March 20, 2026
Problem statement
Given a list of names where each name is a string (may contain multiple words or just one), return a new list sorted by last name. The last name is defined as the last whitespace-separated token in the string after stripping leading/trailing whitespace. Comparison should be case-insensitive but the returned names must be the original strings (preserve original casing and spacing). Use a lambda key with sorted.
Task
Sort a list of full names by last name using a lambda as the key function. Handle single-word names and preserve original spacing in the output.
Examples
Input format
A list of name strings, e.g. ['John Doe', 'Ada Lovelace'].
Output format
A new list of the original name strings sorted by last name.
Constraints
Names may be single-word (treated as last name). Comparison is case-insensitive.
Samples
Sample 1
Input
sort_names_by_last(['Plato', 'Socrates', 'Aristotle'])
Output
['Aristotle', 'Plato', 'Socrates']
Single-word names are sorted alphabetically by that 'last' word.