solve Day13 Part One with python

Day13/python/solution1.py

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+from itertools import groupby
+
+def find_mirror(group):
+    """
+    Find the line of symmetry in the pattern.
+    For vertical symmetry, `group` should be the original group of lines.
+    For horizontal symmetry, `group` should be the transposed group.
+    Returns the position of the line of symmetry or 0 if none found.
+    """
+    for i in range(1, len(group)):
+        above = group[:i][::-1]
+        below = group[i:]
+        if all(a == b for a, b in zip(above, below)):
+            return i
+    return 0
+
+def process_file(filename):
+    """
+    Process the given file to find the sum of mirror lines.
+    Handles both vertical and horizontal reflections.
+    """
+    try:
+        with open(filename) as f:
+            lines = f.read().splitlines()
+
+        groups = [tuple(group) for not_empty, group in groupby(lines, bool) if not_empty]
+
+        res = 0
+        for group in groups:
+            # Vertical reflection
+            res += find_mirror(group) * 100
+            # Horizontal reflection
+            res += find_mirror(tuple(zip(*group)))
+        
+        return res
+
+    except Exception as e:
+        print(f"Error processing file {filename}: {e}")
+        raise
+
+def test():
+    """
+    Test function to verify the algorithm with test data.
+    """
+    try:
+        test_result = process_file("../test.txt")
+        print(f"Test result: {test_result}")
+        assert test_result == 405, "Test failed. Expected result is 405."
+        print("Test passed.")
+    except AssertionError as ae:
+        print(ae)
+    except Exception as e:
+        print(f"Test error: {e}")
+
+def main():
+    """
+    Main function to run the test and then process the actual input file.
+    """
+    print("Starting tests...")
+    test()
+
+    print("\nProcessing main input file...")
+    final_result = process_file("../input.txt")
+    print(f"Final result: {final_result}")
+
+if __name__ == "__main__":
+    main()