Calculate Frequency of Items in Python (Dictionary & Counter)

Question

Given a list of customer search query tags, write a Python function that returns a dictionary mapping each unique tag to its count frequency. Do not use external third-party libraries.

Accepted Answer

Optimal Solution:
from collections import Counter

def count_frequencies(items: list) -> dict:
    # Standard Python dictionary approach
    freq_map = {}
    for item in items:
        freq_map[item] = freq_map.get(item, 0) + 1
    return freq_map

# Alternative clean one-liner:
# return dict(Counter(items))

Technical Explanation:
`freq_map.get(item, 0) + 1` safely fetches the current count or defaults to 0 if the key is seen for the first time. `collections.Counter(items)` does this in C-speed internally.

tag	count
laptop	3
mouse	2
keyboard	1