11.11 Common Algorithms

Search and aggregate operations on a tuple use the exact same techniques as on a list (see 10.12 Sorting and Searching and 10.14 Common Algorithms) — the only difference is a tuple can’t be sorted in place.

Searching

def search(tup, target):
    for i, v in enumerate(tup):
        if v == target:
            return i
    return -1

>>> search((5, 2, 8, 1, 9), 8)
2

Counting

>>> (5, 2, 8, 1, 9).count(2)
1

Finding Maximum / Minimum

>>> max((5, 2, 8, 1, 9)), min((5, 2, 8, 1, 9))
(9, 1)

Quick Interview Answer

“Every list algorithm — linear search, counting, finding extremes — applies to a tuple unchanged, since none of them require mutation, only iteration and comparison. The one thing that genuinely doesn’t carry over is in-place sorting: sorted(some_tuple) works fine and returns a list, but there’s no tuple.sort(), because sorting in place is a contradiction for something that can’t be modified. If a sorted tuple is actually needed, wrap the result: tuple(sorted(t)).”

Common Mistakes

• Reaching for t.sort() on a tuple, forgetting it doesn’t exist — use sorted(t) (returns a list) or tuple(sorted(t)) if a tuple result is needed.
• Writing a custom linear search for a tuple instead of just using in or .index() when only presence or a single position is needed, not every algorithmic detail of the search.
• Assuming binary search needs adapting for tuples — it works identically, since it only relies on indexing and comparison, neither of which differs from a list.