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Sort Dictionary

Zero-dependency Python snippets for sorting dictionaries using the standard library.

8 snippets available in this sub-category.

Simple

Sort by key (ascending)

dict sort key ascending data-structures

Sort dictionary by key (ascending)

d = {"b": 2, "a": 1, "c": 3}
sorted_by_key = dict(sorted(d.items()))
print(sorted_by_key)  # {'a': 1, 'b': 2, 'c': 3}

Notes

  • sorted() returns a list of tuples; wrap with dict() for new dict
  • Preserves order in Python 3.7+

Sort by value (ascending)

dict sort value ascending data-structures

Sort dictionary by value (ascending)

d = {"b": 2, "a": 1, "c": 3}
sorted_by_value = dict(sorted(d.items(), key=lambda item: item[1]))
print(sorted_by_value)  # {'a': 1, 'b': 2, 'c': 3}

Notes

  • key argument sorts by value
  • Stable sort: order of equal values is preserved

Sort by key (descending)

dict sort key descending data-structures

Sort dictionary by key (descending)

d = {"b": 2, "a": 1, "c": 3}
sorted_by_key_desc = dict(sorted(d.items(), reverse=True))
print(sorted_by_key_desc)  # {'c': 3, 'b': 2, 'a': 1}

Notes

  • reverse=True for descending order
  • Preserves order in Python 3.7+

Sort by value (descending)

dict sort value descending data-structures

Sort dictionary by value (descending)

d = {"b": 2, "a": 1, "c": 3}
sorted_by_value_desc = dict(sorted(d.items(), key=lambda item: item[1], reverse=True))
print(sorted_by_value_desc)  # {'c': 3, 'b': 2, 'a': 1}

Notes

  • Use reverse=True to sort values descending
  • Stable sort: order of equal values is preserved

Complex

Sort by custom key (length, function)

dict sort custom function data-structures

Sort dictionary by custom key function

d = {"apple": 5, "banana": 2, "pear": 10}
sorted_by_len = dict(sorted(d.items(), key=lambda item: len(item[0])))
print(sorted_by_len)  # {'pear': 10, 'apple': 5, 'banana': 2}

# Sort by value squared
d = {"a": 2, "b": -3, "c": 1}
sorted_by_val_sq = dict(sorted(d.items(), key=lambda item: item[1] ** 2))
print(sorted_by_val_sq)  # {'c': 1, 'a': 2, 'b': -3}

Notes

  • key can be any function of (key, value)
  • Useful for advanced sorting (e.g., by string length, abs value)

Stable sort (preserve order for equal keys/values)

dict sort stable data-structures

Python's sort is stable (preserves order for equal values)

d = {"a": 2, "b": 2, "c": 1}
sorted_stable = dict(sorted(d.items(), key=lambda item: item[1]))
print(sorted_stable)  # {'c': 1, 'a': 2, 'b': 2}

Notes

  • Order of equal values is preserved
  • Useful for multi-level sorting

Sort nested dictionary by inner value

dict sort nested custom data-structures

Sort dictionary by value of nested key

d = {"a": {"score": 2}, "b": {"score": 1}, "c": {"score": 3}}
sorted_nested = dict(sorted(d.items(), key=lambda item: item[1]["score"]))
print(sorted_nested)  # {'b': {'score': 1}, 'a': {'score': 2}, 'c': {'score': 3}}

Notes

  • Use key=lambda item: item[1]['nested'] for nested dicts
  • Raises KeyError if nested key missing

Edge cases: empty dict, all equal values

dict sort edge-case data-structures

Handle edge cases for sorting

print(dict(sorted({}.items())))  # {}
print(dict(sorted({"a": 1, "b": 1}.items(), key=lambda item: item[1])))  # {'a': 1, 'b': 1}

Notes

  • Sorting empty dict returns empty dict
  • All equal values: preserves original order

🔗 Cross Reference

🏷️ Tags

dict, sort, key, value, custom, stable, nested, edge-case, data-structures

📝 Notes

  • sorted() always returns a list of tuples; wrap with dict() for a new dict
  • Sorting does not modify the original dict