unique_in_order.md

Unique In Order

• Implement the function unique_in_order which takes as argument a sequence and returns a list of items without any elements with the same value next to each other and preserving the original order of elements.

Example

unique_in_order('AAAABBBCCDAABBB') == ['A', 'B', 'C', 'D', 'A', 'B']
unique_in_order('ABBCcAD')         == ['A', 'B', 'C', 'c', 'A', 'D']
unique_in_order([1,2,2,3,3])       == [1,2,3]

Solution :

def unique_in_order(iterable):
    res = []
    for i in iterable:
        if len(res) == 0 or i != res[-1]:
            res.append(i)
    return res

print(unique_in_order('AAAABBBCCDAABBB')) # ['A','B','C','D','A','B']