#### Double Sort

A
a
```def double_sort(lst):
"""This sorting algorithm sorts an array using the principle of bubble sort,
but does it both from left to right and right to left.
Hence, it's called "Double sort"
:param collection: mutable ordered sequence of elements
:return: the same collection in ascending order
Examples:
>>> double_sort([-1 ,-2 ,-3 ,-4 ,-5 ,-6 ,-7])
[-7, -6, -5, -4, -3, -2, -1]
>>> double_sort([])
[]
>>> double_sort([-1 ,-2 ,-3 ,-4 ,-5 ,-6])
[-6, -5, -4, -3, -2, -1]
>>> double_sort([-3, 10, 16, -42, 29]) == sorted([-3, 10, 16, -42, 29])
True
"""
no_of_elements = len(lst)
for _ in range(
0, int(((no_of_elements - 1) / 2) + 1)
):  # we don't need to traverse to end of list as
for j in range(0, no_of_elements - 1):
if (
lst[j + 1] < lst[j]
):  # applying bubble sort algorithm from left to right (or forwards)
temp = lst[j + 1]
lst[j + 1] = lst[j]
lst[j] = temp
if (
lst[no_of_elements - 1 - j] < lst[no_of_elements - 2 - j]
):  # applying bubble sort algorithm from right to left (or backwards)
temp = lst[no_of_elements - 1 - j]
lst[no_of_elements - 1 - j] = lst[no_of_elements - 2 - j]
lst[no_of_elements - 2 - j] = temp
return lst

if __name__ == "__main__":
print("enter the list to be sorted")
lst = [int(x) for x in input().split()]  # inputing elements of the list in one line
sorted_lst = double_sort(lst)
print("the sorted list is")
print(sorted_lst)
```