Solve day 3 (Python)

q3.py

@@ -0,0 +1,33 @@
+import re
+
+MUL_PATTERN = re.compile(r"mul\((\d+), *(\d+)\)")
+def task1(text: str) -> int:
+    total = 0
+    for mul in MUL_PATTERN.finditer(text):
+        a, b = map(int, mul.groups())
+        total += a*b
+    return total
+
+MUL_OR_DO_PATTERN = re.compile(r"do\(\)|don't\(\)|mul\((\d+), *(\d+)\)")
+def task2(text: str) -> int:
+    total = 0
+    on = True
+    for op in MUL_OR_DO_PATTERN.finditer(text):
+        if op.group(0) == "do()":
+            on = True
+        if op.group(0) == "don't()":
+            on = False
+        if op.group(1) and on:
+            a, b = map(int, op.groups())
+            total += a*b
+    return total
+
+def main():
+    with open("i3.txt") as f:
+        text = f.read()
+
+    print(task1(text))
+    print(task2(text))
+
+if __name__ == "__main__":
+    main()