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Stop 1 of 5 · Bike shop: sorting by wheel size
Trick to keep in mind+3 XP
Python's sorted() is guaranteed stable: ties keep input order.
Stable means that two items with equal keys stay in the same relative order as they were given. Sorting ["bb", "a", "cc", "d"] by length gives a, d, bb, cc: a before d and bb before cc, because that is how each tie began. The Python docs promise this, so you can build on it.
words = ["bb", "a", "cc", "d"]
print(sorted(words, key=len)) # ['a', 'd', 'bb', 'cc']Read it once, then a question tests whether the trick stuck.