day 1 part 2 with internal re module

solve.py

@@ -1,26 +1,38 @@
 #!/usr/bin/env python3
 import sys
-import regex as re
+import re
 
 num_values = dict(
-    one=1,
-    two=2,
-    three=3,
-    four=4,
-    five=5,
-    six=6,
-    seven=7,
-    eight=8,
-    nine=9,
+    one="1",
+    two="2",
+    three="3",
+    four="4",
+    five="5",
+    six="6",
+    seven="7",
+    eight="8",
+    nine="9",
 )
 
+patterns = "one two three four five six seven eight nine 1 2 3 4 5 6 7 8 9".split()
+
 sum = 0
 for line in sys.stdin:
-    nums = re.findall(r"one|two|three|four|five|six|seven|eight|nine|[1-9]", line, overlapped=True)
-    nums = [str(num_values.get(x, x)) for x in nums]
-    first = nums[0]
-    last = nums[-1]
-    value = int(first + last)
+    first = len(line)
+    last = 0
+    nums = []
+    for pat in patterns:
+        for m in re.finditer(pat, line):
+            nums.append((m.start(), pat))
+
+    nums.sort()
+    first_word = nums[0][1]
+    last_word = nums[-1][1]
+
+    first_word = num_values.get(first_word, first_word)
+    last_word = num_values.get(last_word, last_word)
+
+    value = int(first_word + last_word)
     sum += value
 
 print(sum)