Solve day 1

01/__main__.py

@@ -0,0 +1,19 @@
+from puzzle import solve_pt_1, solve_pt_2
+from pathlib import Path
+
+
+def main():
+    input = (
+        Path(__file__)
+        .parent.joinpath("calibration_document.txt")
+        .read_text()
+        .strip()
+        .split("\n")
+    )
+    print("Calibration Numbers")
+    print("Part 1 - ", solve_pt_1(input))
+    print("Part 2 - ", solve_pt_2(input))
+
+
+if __name__ == "__main__":
+    main()

01/puzzle.py

@@ -0,0 +1,67 @@
+import re
+
+pt_1_first_digit_pattern = re.compile("([0-9])")
+pt_1_last_digit_pattern = pt_1_first_digit_pattern
+pt_1_symbol_map = {str(n): str(n) for n in range(10)}
+
+pt_2_first_digit_pattern = re.compile(
+    "([0-9]|one|two|three|four|five|six|seven|eight|nine|zero)"
+)
+pt_2_last_digit_pattern = re.compile(
+    "([0-9]|eno|owt|eerht|ruof|evif|xis|neves|thgie|enin|orez)"
+)
+pt_2_symbol_map = {
+    **pt_1_symbol_map,
+    "one": "1",
+    "two": "2",
+    "three": "3",
+    "four": "4",
+    "five": "5",
+    "six": "6",
+    "seven": "7",
+    "eight": "8",
+    "nine": "9",
+    "zero": "0",
+}
+
+
+def _solve(
+    input: list[str],
+    first_digit_pattern: re.Pattern,
+    last_digit_pattern: re.Pattern,
+    symbol_map: dict[str, str],
+) -> int:
+    total = 0
+
+    for line in input:
+        first_digit_match = first_digit_pattern.search(line)
+        last_digit_match = last_digit_pattern.search(line[::-1])
+
+        if not first_digit_match or not last_digit_match:
+            raise ValueError(f'Line "{line}" calibration document contains no digits.')
+
+        first_digit = symbol_map[first_digit_match.group(1)]
+        last_digit = symbol_map[last_digit_match.group(1)[::-1]]
+
+        line_calibration_number = int(first_digit + last_digit)
+        total += line_calibration_number
+
+    return total
+
+
+def solve_pt_1(input: list[str]) -> int:
+    return _solve(
+        input,
+        pt_1_first_digit_pattern,
+        pt_1_first_digit_pattern,
+        pt_1_symbol_map,
+    )
+
+
+def solve_pt_2(input: list[str]) -> int:
+    return _solve(
+        input,
+        pt_2_first_digit_pattern,
+        pt_2_last_digit_pattern,
+        pt_2_symbol_map,
+    )

01/puzzle_test.py

@@ -0,0 +1,37 @@
+from puzzle import (
+    pt_1_first_digit_pattern,
+    pt_1_last_digit_pattern,
+    solve_pt_1,
+    solve_pt_2,
+)
+
+
+def test_solve_pt_1():
+    assert (
+        solve_pt_1(
+            [
+                "1abc2",
+                "pqr3stu8vwx",
+                "a1b2c3d4e5f",
+                "treb7uchet",
+            ]
+        )
+        == 142
+    )
+
+
+def test_solve_pt_2():
+    assert (
+        solve_pt_2(
+            [
+                "two1nine",
+                "eightwothree",
+                "abcone2threexyz",
+                "xtwone3four",
+                "4nineeightseven2",
+                "zoneight234",
+                "7pqrstsixteen",
+            ]
+        )
+        == 281
+    )