handle 7 digits

Author: jbrockmendel

pandas/_libs/tslibs/timedeltas.pyx

@@ -688,7 +688,7 @@ cdef bint needs_nano_unit(int64_t ival, str item):
     # TODO: more performant way of doing this check?
     if ival % 1000 != 0:
         return True
-    return re.search(r"\.\d{9}", item) or "ns" in item or "nano" in item
+    return re.search(r"\.\d{7}", item) or "ns" in item or "nano" in item
 
 
 cpdef inline str parse_timedelta_unit(str unit):

pandas/tests/scalar/timedelta/test_constructors.py

@@ -717,5 +717,9 @@ def test_parsed_unit():
     td = Timedelta("1 Day 2:03:04.012345")
     assert td.unit == "us"
 
-    td = Timedelta("1 Day 2:03:04.012345123")
+    td = Timedelta("1 Day 2:03:04.012345000")
+    assert td.unit == "ns"
+
+    # 7 digits after the decimal
+    td = Timedelta("1 Day 2:03:04.0123450")
     assert td.unit == "ns"