{k: v for k, v in sorted(my_dict.items(), key=lambda item: item

Built-in Data Structures

Meaning

It builds a new dictionary whose entries are ordered by their values in ascending order. This helps when deterministic iteration over a mapping is required, such as generating ranked reports or stable serializations. Use it whenever you need to process a dictionary in value order without mutating the original mapping.

Primary Function

Data transformation

Communicative Purpose

Sort a dictionary by its values to produce an ordered dictionary for deterministic iteration.

Pattern

{key: value for key, value in sorted(data.items(), key=lambda pair: pair[1])}

Core Structure

{... for ... in sorted(... .items(), key=lambda ...: ...)}

Função primária

Data transformation

Propósito comunicativo

Sort a dictionary by its values to produce an ordered dictionary for deterministic iteration.

Situações de gatilho

When you need to process dictionary items in order of increasing value, e.g., ranking, priority queues, or displaying results sorted by score.

Contextos

Data processing scripts, analytics, configuration handling, any code that requires ordered iteration over a mapping by value.

Padrão

{key: value for key, value in sorted(data.items(), key=lambda pair: pair[1])}

Estrutura central

{... for ... in sorted(... .items(), key=lambda ...: ...)}

Slots de substituição

data: dict-like mapping to sort; key, value: loop variables for each item; pair: variable representing each (key, value) tuple.

Colocados típicos

operator.itemgetter
collections.OrderedDict
reverse flag
dict() constructor.

Substituições comuns

Using dict(sorted(data.items()
key=operator.itemgetter(1))) or dict(sorted(data.items()
key=lambda kv: kv[1])).

Erros comuns

Assuming order is preserved in Python <3.6; forgetting that the comprehension builds a new dict, not sorting in-place; using a lambda that returns the wrong index (e.g., item[0] for key).

Similar / contraste

Sorting by key: {k: v for k, v in sorted(data.items())} (orders by keys); sorting by value descending: same pattern with reverse=True.

Interferências

Coming from languages with unordered maps (e.g., Java HashMap, C++ unordered_map) may expect order to be irrelevant; in Python 3.7+ dict preserves insertion order, so the result is ordered.

Família do chunk

dict comprehension
sorting
lambda
ordered dict

Nuance

Only guarantees order preservation in Python 3.7+ (implementation detail in 3.6). If values are not comparable, a TypeError is raised. The original dictionary is unchanged.

Efeito pragmático

Produces a deterministic ordering for iteration, debugging, or serialization where stable order matters.

Dica de memória

Sort by value, keep keys.

Nota

Only works as expected in Python 3.7+ where dict preserves insertion order.

Upgrade path

from operator import itemgetter; dict(sorted(data.items(), key=itemgetter(1)))

Frequência: MediumFormulaicidade: Semi-fixedTipo de construção: comprehensionPrioridade de aquisição: Active recallPrioridade de output: BothTag de espaçamento: Medium-term

Examples

scores = {'alice': 85, 'bob': 92, 'charlie': 78} ordered = {name: score for name, score in sorted(scores.items(), key=lambda item: item[1])} print(ordered) # {'charlie': 78, 'alice': 85, 'bob': 92}

prices = {'apple': 1.2, 'banana': 0.5, 'orange': 0.8} cheap_first = {f: p for f, p in sorted(prices.items(), key=lambda item: item[1], reverse=True)} print(cheap_first) # {'apple': 1.2, 'orange': 0.8, 'banana': 0.5}

from operator import itemgetter inventory = {'widget': 10, 'gadget': 5, 'thing': 20} sorted_inv = dict(sorted(inventory.items(), key=itemgetter(1))) print(sorted_inv) # {'gadget': 5, 'widget': 10, 'thing': 20}