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First solution in Clear category for Sort Array by Element Frequency by nomis517
def frequency_sort(items):
grouped_list = []
uniq_elems = set()
for elem in items:
if elem not in uniq_elems:
uniq_elems.add(elem)
grouped_list.extend([elem] * items.count(elem))
return sorted(grouped_list, key=lambda elem: items.count(elem), reverse=True)
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!")
Feb. 16, 2020
