diff --git a/2021-python/solutions/day_06.py b/2021-python/solutions/day_06.py
new file mode 100644
index 0000000..d8d160c
--- /dev/null
+++ b/2021-python/solutions/day_06.py
@@ -0,0 +1,30 @@
+from solutions import BaseSolution
+
+
+class Solution(BaseSolution):
+    input_file = "06.txt"
+
+    def __str__(self):
+        return "Day 6: Lanternfish"
+
+    def parse_input(self, data):
+        return list(map(int, data.strip().split(",")))
+
+    def solve(self, puzzle_input):
+        return self._produce(puzzle_input, 80)
+
+    def solve_again(self, puzzle_input):
+        return self._produce(puzzle_input, 256)
+
+    def _produce(self, puzzle_input, tf):
+        f = [*puzzle_input]
+        for _ in range(tf):
+            n = [8 for __ in range(sum(x <= 0 and x % 7 == 0 for x in f))]
+            f = list(map(lambda x: x - 1, f))
+            f.extend(n)
+        return len(f)
+
+
+if __name__ == "__main__":
+    solution = Solution()
+    solution.show_results()
diff --git a/2021-python/tests/test_day_06.py b/2021-python/tests/test_day_06.py
new file mode 100644
index 0000000..7b4fd3d
--- /dev/null
+++ b/2021-python/tests/test_day_06.py
@@ -0,0 +1,29 @@
+import unittest
+
+from solutions.day_06 import Solution
+
+
+class Day06TestCase(unittest.TestCase):
+    def setUp(self):
+        self.solution = Solution()
+        self.puzzle_input = self.solution.parse_input(
+            """
+        3,4,3,1,2
+        """
+        )
+
+    def test_parse_puzzle_input(self):
+        data = """
+        3,4,3,1,2
+        """
+        assert self.solution.parse_input(data) == [3, 4, 3, 1, 2]
+
+    def test_solve_first_part(self):
+        assert self.solution.solve(self.puzzle_input) == 5934
+
+    # def test_solve_second_part(self):
+    #    assert self.solution.solve_again(self.puzzle_input) == 26984457539
+
+
+if __name__ == "__main__":
+    unittest.main()