bucket_sort.py3

# taken from discussion -- not original code
n = int(input().strip())
bucket = defaultdict(list) # bucket, actually a list with 1 key/n values

# store each input in the appropriate sub-bucket location
# use the string's length as the index (key), and appends it at that sub-bucket location
# this collects all string of the same length in the same sub-bucket location
for _ in range(n):
    number = input().strip()
    bucket[len(number)].append(number)

# the bucket is then sorted in terms of length, and the items within each sub-bucket are
# then sorted alphabetically (thanks to python)
for key in sorted(bucket):
    for value in sorted(bucket[key]): # each value in the sub-bucket is sorted alphabetically (thanks python!)
        print(value)