issue_comments: 567018062

Another issue with datetime_to_numeric happens with: import xarray as xr import cftime i = xr.CFTimeIndex(xr.cftime_range('2000-01-01', periods=2)) xr.core.duck_array_ops.datetime_to_numeric(i, cftime.DatetimeGregorian(2, 1, 1), datetime_unit='D')

```python

TypeError Traceback (most recent call last) pandas/_libs/tslibs/timedeltas.pyx in pandas._libs.tslibs.timedeltas.array_to_timedelta64()

pandas/_libs/tslibs/timedeltas.pyx in pandas._libs.tslibs.timedeltas.parse_timedelta_string()

TypeError: object of type 'datetime.timedelta' has no len()

During handling of the above exception, another exception occurred:

OverflowError Traceback (most recent call last) <ipython-input-50-b03d9c4f220d> in <module> ----> 1 xr.core.duck_array_ops.datetime_to_numeric(i, cftime.DatetimeGregorian(2, 1, 1), datetime_unit='D')

~/src/xarray/xarray/core/duck_array_ops.py in datetime_to_numeric(array, offset, datetime_unit, dtype) 395 else: 396 offset = min(array) --> 397 array = array - offset 398 399 if not hasattr(array, "dtype"): # scalar is converted to 0d-array

~/src/xarray/xarray/coding/cftimeindex.py in sub(self, other) 431 432 if isinstance(other, (CFTimeIndex, cftime.datetime)): --> 433 return pd.TimedeltaIndex(np.array(self) - np.array(other)) 434 elif isinstance(other, pd.TimedeltaIndex): 435 return CFTimeIndex(np.array(self) - other.to_pytimedelta())

~/.conda/envs/xclim3/lib/python3.6/site-packages/pandas/core/indexes/timedeltas.py in new(cls, data, unit, freq, start, end, periods, closed, dtype, copy, name, verify_integrity) 256 257 tdarr = TimedeltaArray._from_sequence( --> 258 data, freq=freq, unit=unit, dtype=dtype, copy=copy 259 ) 260 return cls._simple_new(tdarr._data, freq=tdarr.freq, name=name)

~/.conda/envs/xclim3/lib/python3.6/site-packages/pandas/core/arrays/timedeltas.py in _from_sequence(cls, data, dtype, copy, freq, unit) 270 freq, freq_infer = dtl.maybe_infer_freq(freq) 271 --> 272 data, inferred_freq = sequence_to_td64ns(data, copy=copy, unit=unit) 273 freq, freq_infer = dtl.validate_inferred_freq(freq, inferred_freq, freq_infer) 274

~/.conda/envs/xclim3/lib/python3.6/site-packages/pandas/core/arrays/timedeltas.py in sequence_to_td64ns(data, copy, unit, errors) 971 if is_object_dtype(data.dtype) or is_string_dtype(data.dtype): 972 # no need to make a copy, need to convert if string-dtyped --> 973 data = objects_to_td64ns(data, unit=unit, errors=errors) 974 copy = False 975

~/.conda/envs/xclim3/lib/python3.6/site-packages/pandas/core/arrays/timedeltas.py in objects_to_td64ns(data, unit, errors) 1096 values = np.array(data, dtype=np.object_, copy=False) 1097 -> 1098 result = array_to_timedelta64(values, unit=unit, errors=errors) 1099 return result.view("timedelta64[ns]") 1100

pandas/_libs/tslibs/timedeltas.pyx in pandas._libs.tslibs.timedeltas.array_to_timedelta64()

pandas/_libs/tslibs/timedeltas.pyx in pandas._libs.tslibs.timedeltas.convert_to_timedelta64()

pandas/_libs/tslibs/timedeltas.pyx in pandas._libs.tslibs.timedeltas.delta_to_nanoseconds()

OverflowError: Python int too large to convert to C long ```