Sort and secondary sort

We have a list of words. It is easy to sort them by length, but what will be the order among the words that have the same length?

A sort using a lambda-function that returns a tuple can provide the secondary sort order.

examples/lists/sort_by_two_keys.py

planets1 = ['Mercury', 'Venus', 'Earth', 'Mars', 'Jupiter', 'Saturn']
planets2 = ['Mercury', 'Earth', 'Venus', 'Mars', 'Jupiter', 'Saturn']

print(sorted(planets1, key=len))
# ['Mars', 'Venus', 'Earth', 'Saturn', 'Mercury', 'Jupiter']
print(sorted(planets2, key=len))
# ['Mars', 'Earth', 'Venus', 'Saturn', 'Mercury', 'Jupiter']

print(sorted(planets1, key=lambda w: (len(w), w)))
# ['Mars', 'Earth', 'Venus', 'Saturn', 'Jupiter', 'Mercury']
print(sorted(planets2, key=lambda w: (len(w), w)))
# ['Mars', 'Earth', 'Venus', 'Saturn', 'Jupiter', 'Mercury']