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Convert Dictionary to List (Guide)

Zero-dependency Python snippets for converting dictionaries to lists using the standard library.

11 snippets available in this sub-category.

Simple

Get list of keys

dict to-list keys data-structures

Convert dict keys to list

d = {"a": 1, "b": 2, "c": 3}
keys = list(d.keys())
print(keys)  # ['a', 'b', 'c']

Notes

  • Order matches insertion order (Python 3.7+)
  • Returns empty list for empty dict

Get list of values

dict to-list values data-structures

Convert dict values to list

d = {"a": 1, "b": 2, "c": 3}
values = list(d.values())
print(values)  # [1, 2, 3]

Notes

  • Order matches insertion order
  • Values can be any type

Get list of (key, value) tuples

dict to-list items tuple data-structures

Convert dict items to list of tuples

d = {"a": 1, "b": 2, "c": 3}
items = list(d.items())
print(items)  # [('a', 1), ('b', 2), ('c', 3)]

Notes

  • Each tuple is (key, value)
  • Useful for iteration and unpacking

Advanced Patterns

Flatten nested dict to list of (outer, inner, value)

dict to-list flatten nested data-structures

Flatten nested dict to list of tuples

nested = {"a": {"x": 1}, "b": {"y": 2}}
flat = [(k, ik, iv) for k, v in nested.items() for ik, iv in v.items()]
print(flat)  # [('a', 'x', 1), ('b', 'y', 2)]

Notes

  • Only works for two-level nesting
  • Useful for tabular data

List of keys/values/items with filtering

dict to-list filter data-structures

Filtered lists from dict

d = {"a": 1, "b": 2, "c": 3}
even_keys = [k for k, v in d.items() if v % 2 == 0]
print(even_keys)  # ['b']

values_gt1 = [v for v in d.values() if v > 1]
print(values_gt1)  # [2, 3]

Notes

  • List comprehensions allow flexible filtering
  • Can filter by key or value

List of sorted keys/values/items

dict to-list sort data-structures

Sorted lists from dict

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

Notes

  • sorted() returns a new list
  • Can sort by key or value

List of unique values

dict to-list unique values data-structures

Get unique values from dict

d = {"a": 1, "b": 2, "c": 1}
unique_values = list(set(d.values()))
print(unique_values)  # [1, 2]

Notes

  • set() removes duplicates
  • Order is not preserved

List of keys/values/items with transformation

dict to-list transform data-structures

Transform keys/values to list

d = {"a": 1, "b": 2}
keys_upper = [k.upper() for k in d]
print(keys_upper)  # ['A', 'B']
values_squared = [v**2 for v in d.values()]
print(values_squared)  # [1, 4]

Notes

  • Use comprehensions for transformation
  • Can apply any function to keys or values

List of dicts from list of keys/values

dict to-list keys values data-structures

Build list of single-item dicts

keys = ["a", "b"]
values = [1, 2]
dicts = [{k: v} for k, v in zip(keys, values)]
print(dicts)  # [{'a': 1}, {'b': 2}]

Notes

  • Each dict has one key-value pair
  • Useful for splitting data

Performance and Edge Cases

Large dicts (performance)

dict to-list performance data-structures

Converting large dicts to lists is fast

import time

N = 10**6
d = {x: x * 2 for x in range(N)}
start = time.time()
keys = list(d.keys())
print("Time:", time.time() - start)

Notes

  • list() is efficient for large dicts
  • Performance depends on dict size

Edge cases: empty dict, non-hashable values

dict to-list edge-case data-structures

Handle edge cases for dict to list

print(list({}.keys()))  # []
print(list({}.values()))  # []
print(list({}.items()))  # []

Notes

  • Empty dict returns empty lists
  • Works for any dict type

🔗 Cross Reference

🏷️ Tags

dict, to-list, keys, values, items, flatten, filter, sort, unique, transform, performance, edge-case, data-structures

📝 Notes

  • Use list() to convert dict views to lists
  • List comprehensions allow filtering and transformation