Find Keys Common to All Dicts

Medium ⏱ 12 min 47% acceptance ★★★★☆ 4.4

Write a function common_keys(dict_list) that takes a list of dicts and returns a sorted list of keys that are present in every dict in dict_list. If dict_list is empty, return an empty list.

Examples

Example 1

Input

common_keys([{'a': 1, 'b': 2}, {'a': 5, 'b': 6, 'c': 7}, {'a': 9, 'b': 0}])

Output

['a', 'b']

Explanation

'a' and 'b' appear in all three dicts; 'c' only in the second.

Constraints

Return sorted order.
Empty input list returns [].

Topics

Dictionariesset operations

Companies

OracleIBM

Hints

Hint 1

Convert each dict's keys to a set, then intersect all sets with `set.intersection(*sets)`.

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