Item frequency count in Python
Solution 1:
The Counter class in the collections module is purpose built to solve this type of problem:
from collections import Counter
words = "apple banana apple strawberry banana lemon"
Counter(words.split())
# Counter({'apple': 2, 'banana': 2, 'strawberry': 1, 'lemon': 1})
Solution 2:
defaultdict to the rescue!
from collections import defaultdict
words = "apple banana apple strawberry banana lemon"
d = defaultdict(int)
for word in words.split():
d[word] += 1
This runs in O(n).