Attempt unit us to_datetime

Author: Pranav-Wadhwa

pandas/core/tools/datetimes.py

@@ -672,7 +672,7 @@ def to_datetime(
     utc: bool = False,
     format: str | None = None,
     exact: bool | lib.NoDefault = lib.no_default,
-    unit: str | None = None,
+    unit: str | None = "us",
     origin: str = "unix",
     cache: bool = True,
 ) -> DatetimeIndex | Series | DatetimeScalar | NaTType | None:

pandas/tests/tools/test_to_datetime.py

@@ -1714,6 +1714,19 @@ def test_to_datetime_mixed_offsets_with_utc_false_removed(self, date):
         with pytest.raises(ValueError, match=msg):
             to_datetime(date, utc=False)
 
+    @pytest.mark.parametrize(
+        "date",
+        [
+            "2024-03-22 11:43:01",
+            "2024-03-22 11:43:01.002",
+            "2024-03-22 11:43:01.002003",
+        ],
+    )
+    def test_to_datetime_type(self, date):
+        dt = to_datetime([date])
+        print("pranav dtype is ", dt.dtype)
+        assert dt.dtype == "<M8[us]"
+
 
 class TestToDatetimeUnit:
     @pytest.mark.parametrize("unit", ["Y", "M"])