Scale ISO 8601 duration fractions by their digit count

The pure-Python parser divided the fractional part by 10 regardless of
length, so P1.25D read as 1 day plus 60 hours. Only single-digit
fractions were correct, and the four components shared the assumption.

Author: ckarnell

src/pendulum/parsing/iso8601.py

@@ -296,7 +296,7 @@ def _parse_iso8601_duration(text: str, **options: str) -> Duration | None:
         if "." in _weeks:
             _weeks, portion = _weeks.split(".")
             weeks = int(_weeks)
-            _days = int(portion) / 10 * 7
+            _days = int(portion) / 10 ** len(portion) * 7
             days, hours = int(_days // 1), int(_days % 1 * HOURS_PER_DAY)
         else:
             weeks = int(_weeks)
@@ -344,7 +344,7 @@ def _parse_iso8601_duration(text: str, **options: str) -> Duration | None:
 
                 _days, _hours = _days.split(".")
                 days = int(_days)
-                hours = int(_hours) / 10 * HOURS_PER_DAY
+                hours = int(_hours) / 10 ** len(_hours) * HOURS_PER_DAY
             else:
                 days = int(_days)
 
@@ -374,7 +374,7 @@ def _parse_iso8601_duration(text: str, **options: str) -> Duration | None:
 
                 _hours, _mins = _hours.split(".")
                 hours += int(_hours)
-                minutes += int(_mins) / 10 * MINUTES_PER_HOUR
+                minutes += int(_mins) / 10 ** len(_mins) * MINUTES_PER_HOUR
             else:
                 hours += int(_hours)
 
@@ -389,7 +389,7 @@ def _parse_iso8601_duration(text: str, **options: str) -> Duration | None:
 
                 _minutes, _secs = _minutes.split(".")
                 minutes += int(_minutes)
-                seconds += int(_secs) / 10 * SECONDS_PER_MINUTE
+                seconds += int(_secs) / 10 ** len(_secs) * SECONDS_PER_MINUTE
             else:
                 minutes += int(_minutes)
 

tests/parsing/test_parsing_duration.py

@@ -304,3 +304,21 @@ def test_parse_interval_invalid():
 def test_parse_duration_fraction_only_allowed_on_last_component():
     with pytest.raises(ParserError):
         parse("P2Y3M4DT5.5H6M7S")
+
+
+@pytest.mark.parametrize(
+    "text, seconds",
+    [
+        ("P1.5D", 129600),   # one fractional digit, already correct
+        ("P1.25D", 108000),
+        ("PT1.25H", 4500),
+        ("PT1.05M", 63),
+        ("P1.25W", 756000),
+    ],
+)
+def test_parse_duration_multi_digit_fraction(text, seconds):
+    # Imports the pure-Python parser directly: `parse` uses the Rust extension
+    # unless PENDULUM_EXTENSIONS=0, so going through it would not exercise this.
+    from pendulum.parsing.iso8601 import parse_iso8601
+
+    assert parse_iso8601(text).total_seconds() == seconds