dedupe_keep_first: Python exercise

Your mission

Implement dedupe_keep_first, which returns the strings of values without duplicates, each one kept where it first appears and spelled as it was.

dedupe_keep_first(["pear", "fig", "pear", "kiwi", "fig"], False): ['pear', 'fig', 'kiwi']
dedupe_keep_first(["Tea", "tea", "TEA", "Mate"], True): ['Tea', 'Mate']
dedupe_keep_first(["Tea", "tea", "TEA", "Mate"], False): ['Tea', 'tea', 'TEA', 'Mate']
dedupe_keep_first([], True): []

values is a list of strings, possibly empty. A string may be empty and holds only ASCII characters.
Keep one value per group of duplicates, the first occurrence. Kept values stay in the order they have in values.
When ignore_case is True, two values that differ only in the case of some of their letters are duplicates, and the kept value is spelled exactly as its first occurrence.
When ignore_case is False, two values are duplicates only when they are exactly equal.
Return a new list and do not modify values.

Implement dedupe_keep_first, which returns the strings of values without duplicates, each one kept where it first appears and spelled as it was.

dedupe_keep_first(["pear", "fig", "pear", "kiwi", "fig"], False): ['pear', 'fig', 'kiwi']
dedupe_keep_first(["Tea", "tea", "TEA", "Mate"], True): ['Tea', 'Mate']
dedupe_keep_first(["Tea", "tea", "TEA", "Mate"], False): ['Tea', 'tea', 'TEA', 'Mate']
dedupe_keep_first([], True): []

values is a list of strings, possibly empty. A string may be empty and holds only ASCII characters.
Keep one value per group of duplicates, the first occurrence. Kept values stay in the order they have in values.
When ignore_case is True, two values that differ only in the case of some of their letters are duplicates, and the kept value is spelled exactly as its first occurrence.
When ignore_case is False, two values are duplicates only when they are exactly equal.
Return a new list and do not modify values.

Implement dedupe_keep_first, which returns the strings of values without duplicates, each one kept where it first appears and spelled as it was.

dedupe_keep_first(["pear", "fig", "pear", "kiwi", "fig"], False): ['pear', 'fig', 'kiwi']
dedupe_keep_first(["Tea", "tea", "TEA", "Mate"], True): ['Tea', 'Mate']
dedupe_keep_first(["Tea", "tea", "TEA", "Mate"], False): ['Tea', 'tea', 'TEA', 'Mate']
dedupe_keep_first([], True): []

values is a list of strings, possibly empty. A string may be empty and holds only ASCII characters.
Keep one value per group of duplicates, the first occurrence. Kept values stay in the order they have in values.
When ignore_case is True, two values that differ only in the case of some of their letters are duplicates, and the kept value is spelled exactly as its first occurrence.
When ignore_case is False, two values are duplicates only when they are exactly equal.
Return a new list and do not modify values.

Implement dedupe_keep_first, which returns the strings of values without duplicates, each one kept where it first appears and spelled as it was.

dedupe_keep_first(["pear", "fig", "pear", "kiwi", "fig"], False): ['pear', 'fig', 'kiwi']
dedupe_keep_first(["Tea", "tea", "TEA", "Mate"], True): ['Tea', 'Mate']
dedupe_keep_first(["Tea", "tea", "TEA", "Mate"], False): ['Tea', 'tea', 'TEA', 'Mate']
dedupe_keep_first([], True): []

values is a list of strings, possibly empty. A string may be empty and holds only ASCII characters.
Keep one value per group of duplicates, the first occurrence. Kept values stay in the order they have in values.
When ignore_case is True, two values that differ only in the case of some of their letters are duplicates, and the kept value is spelled exactly as its first occurrence.
When ignore_case is False, two values are duplicates only when they are exactly equal.
Return a new list and do not modify values.