fn to remove duplicate ocurrences from a list, in either order (preserves original order), not in-place

remove_dupes_first_last.py

from typing import Final, TypeVar

T = TypeVar('T')

def remove_dupes(inp: list[T], keep_last: bool = False) -> list[T]:
	'''
	creates a list from input,
	such that all ocurrences (but 1) of each value are removed
	(order is preserved).

	if `keep_last`,
	it removes all but the last ocurrence,
	otherwise all but the 1st
	'''
	seen: Final[set[T]] = set()
	out: Final[list[T]] = []
	for x in (reversed(inp) if keep_last else inp):
		if x not in seen:
			seen.add(x)
			out.append(x)
	if keep_last:
		out.reverse()
	return out

# LICENSE: https://unlicense.org