Accept Decimal timestamps in fromtimestamp and utcfromtimestamp

arrow/arrow.py

@@ -12,6 +12,7 @@
 from datetime import time as dt_time
 from datetime import timedelta, timezone
 from datetime import tzinfo as dt_tzinfo
+from decimal import Decimal
 from math import trunc
 from time import struct_time
 from typing import (
@@ -238,17 +239,21 @@ def utcnow(cls) -> "Arrow":
     @classmethod
     def fromtimestamp(
         cls,
-        timestamp: Union[int, float, str],
+        timestamp: Union[int, float, str, Decimal],
         tzinfo: Optional[TZ_EXPR] = None,
     ) -> "Arrow":
         """Constructs an :class:`Arrow <arrow.arrow.Arrow>` object from a timestamp, converted to
         the given timezone.
 
-        :param timestamp: an ``int`` or ``float`` timestamp, or a ``str`` that converts to either.
+        :param timestamp: an ``int``, ``float`` or ``Decimal`` timestamp, or a ``str`` that
+            converts to one of those.
         :param tzinfo: (optional) a ``tzinfo`` object.  Defaults to local time.
 
         """
 
+        if isinstance(timestamp, Decimal):
+            timestamp = float(timestamp)
+
         if tzinfo is None:
             tzinfo = dt_datetime.now().astimezone().tzinfo
         elif isinstance(tzinfo, str):
@@ -273,13 +278,17 @@ def fromtimestamp(
         )
 
     @classmethod
-    def utcfromtimestamp(cls, timestamp: Union[int, float, str]) -> "Arrow":
+    def utcfromtimestamp(cls, timestamp: Union[int, float, str, Decimal]) -> "Arrow":
         """Constructs an :class:`Arrow <arrow.arrow.Arrow>` object from a timestamp, in UTC time.
 
-        :param timestamp: an ``int`` or ``float`` timestamp, or a ``str`` that converts to either.
+        :param timestamp: an ``int``, ``float`` or ``Decimal`` timestamp, or a ``str`` that
+            converts to one of those.
 
         """
 
+        if isinstance(timestamp, Decimal):
+            timestamp = float(timestamp)
+
         if not util.is_timestamp(timestamp):
             raise ValueError(f"The provided timestamp {timestamp!r} is invalid.")
 

tests/test_arrow.py

@@ -7,6 +7,7 @@
 import sys
 import time
 from datetime import date, datetime, timedelta, timezone
+from decimal import Decimal
 from typing import List
 
 import dateutil
@@ -140,6 +141,18 @@ def test_fromtimestamp(self):
         with pytest.raises(ValueError):
             arrow.Arrow.fromtimestamp("invalid timestamp")
 
+    def test_fromtimestamp_decimal(self):
+        # arrow.get() accepts a Decimal timestamp, so the constructor it stands
+        # in for has to accept one too.
+        timestamp = Decimal("1591328104.308505")
+
+        result = arrow.Arrow.fromtimestamp(timestamp, tzinfo="Europe/Paris")
+
+        assert_datetime_equality(
+            result._datetime,
+            datetime.fromtimestamp(float(timestamp), ZoneInfo("Europe/Paris")),
+        )
+
     def test_utcfromtimestamp(self):
         timestamp = time.time()
 
@@ -151,6 +164,15 @@ def test_utcfromtimestamp(self):
         with pytest.raises(ValueError):
             arrow.Arrow.utcfromtimestamp("invalid timestamp")
 
+    def test_utcfromtimestamp_decimal(self):
+        timestamp = Decimal("1591328104.308505")
+
+        result = arrow.Arrow.utcfromtimestamp(timestamp)
+
+        assert result._datetime == datetime(
+            2020, 6, 5, 3, 35, 4, 308505, tzinfo=timezone.utc
+        )
+
     def test_fromdatetime(self):
         dt = datetime(2013, 2, 3, 12, 30, 45, 1)