Level 3Exercise #57

Count without get

Build a frequency dictionary without dict.get or missing-key checks.

What you’ll practice

This Level 3 exercise focuses on defaultdict(int) in the Collections curriculum. Solve the challenge prompt above using clear, idiomatic Python and the relevant language or standard-library tools.

Relevant Python reference: collections.defaultdict.

Sample Test Cases

Example #1

Input:counts(['a','b','a'])

Output:{'a':2,'b':1}

Reference Solution

Reveal Reference Solution

def counts(values: list[str]) -> dict[str, int]:
    from collections import defaultdict
    result = defaultdict(int)
    for value in values:
        result[value] += 1
    return dict(result)

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Count without get

What you’ll practice

Sample Test Cases

Further Reading

Reference Solution