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OrderedDict, sorted(), range(), append() solution in Clear category for Sort Array by Element Frequency by wdmwilcox
def frequency_sort(items):
from collections import OrderedDict
items_dict = OrderedDict()
new_items = []
for item in items:
if item in items_dict:
items_dict[item] += 1
else:
items_dict[item] = 1
for k, v in sorted(items_dict.items(), key=lambda x: x[1], reverse=True):
for i in range(v):
new_items.append(k)
return new_items
if __name__ == '__main__':
print("Example:")
print(frequency_sort([4, 6, 2, 2, 6, 4, 4, 4]))
# These "asserts" are used for self-checking and not for an auto-testing
assert list(frequency_sort([4, 6, 2, 2, 6, 4, 4, 4])) == [4, 4, 4, 4, 6, 6, 2, 2]
assert list(frequency_sort(['bob', 'bob', 'carl', 'alex', 'bob'])) == ['bob', 'bob', 'bob', 'carl', 'alex']
assert list(frequency_sort([17, 99, 42])) == [17, 99, 42]
assert list(frequency_sort([])) == []
assert list(frequency_sort([1])) == [1]
print("Coding complete? Click 'Check' to earn cool rewards!")
April 28, 2020