from collections import OrderedDict

my_list = [1, 2, 2, 3, 1, 4, 5, 3]

# Method 1: Using collections.OrderedDict (most common and clear)
# Keys in OrderedDict are unique and preserve insertion order.
unique_list_ordered = list(OrderedDict.fromkeys(my_list))
# print(unique_list_ordered) # Output: [1, 2, 3, 4, 5]

# Method 2: Using a loop with a set (more verbose but explicit)
seen = set()
unique_list_loop = []
for item in my_list:
    if item not in seen:
        unique_list_loop.append(item)
        seen.add(item)
# print(unique_list_loop) # Output: [1, 2, 3, 4, 5]