Remove Duplicates from List
Remove duplicate elements while preserving order.
Code
Python
# Preserve order (Python 3.7+)
items = [1, 2, 2, 3, 1, 4, 3]
seen = set()
unique = []
for x in items:
if x not in seen:
seen.add(x)
unique.append(x)
print(unique) # [1, 2, 3, 4]
# Or: list(dict.fromkeys(items))Line-by-line explanation
- 1.Use a set to track seen elements.
- 2.Append only if not already seen.
- 3.Preserves insertion order.
- 4.Alternative: dict.fromkeys(items) removes dupes, keys preserve order.
Expected output
[1, 2, 3, 4]