diff --git a/2015-python/inputs/day_4 b/2015-python/inputs/day_4
new file mode 100644
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--- /dev/null
+++ b/2015-python/inputs/day_4
@@ -0,0 +1 @@
+iwrupvqb
diff --git a/2015-python/solutions/day_4.py b/2015-python/solutions/day_4.py
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index 0000000..cd549de
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+++ b/2015-python/solutions/day_4.py
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+"""AOC 2015 Day 4"""
+
+import pathlib
+import time
+import hashlib
+
+TEST_INPUT = """abcdef"""
+
+def read_input(input_path: str) -> str:
+    """take input file path and return a str with the file's content"""
+    with open(input_path, 'r') as input_file:
+        input_data = input_file.read().strip()
+        return input_data
+
+def part1(secret: str) -> int:
+    """part1 solver"""
+    number = 1
+    while True:
+        key = secret + str(number)
+        md5 = hashlib.md5(key.encode()).hexdigest()
+        if md5.startswith('00000'):
+            return number
+        number += 1
+
+def part2(secret: list) -> int:
+    """part2 solver"""
+    number = 1
+    while True:
+        key = secret + str(number)
+        md5 = hashlib.md5(key.encode()).hexdigest()
+        if md5.startswith('000000'):
+            return number
+        number += 1
+
+def test_input_day_4():
+    """pytest testing function"""
+    assert part1(TEST_INPUT) == 609043
+    assert part2(TEST_INPUT) == 6742839
+
+def test_bench_day_4(benchmark):
+    """pytest-benchmark function"""
+    benchmark(main)
+
+def main():
+    """main function"""
+    input_path = str(pathlib.Path(__file__).resolve().parent.parent) + "/inputs/" + str(pathlib.Path(__file__).stem)
+    start_time = time.time()
+    input_data = read_input(input_path)
+    print("Part 1: %d" % part1(input_data))
+    print("Part 2: %d" % part2(input_data))
+    end_time = time.time()
+    print("Execution time: %f" % (end_time-start_time))
+
+if __name__ == "__main__":
+    main()