import pandas as pd import numpy as np dti = pd.date_range('2018-01-01', periods=100, freq='T') dtd = dti[1:] - dti[:-1] print(np.sum(dtd))

--------------------------------------------------------------------------- TypeError Traceback (most recent call last) <ipython-input-1-d64fe48d0fec> in <module> 6 7 print(np.mean(dtd)) # works ----> 8 print(np.sum(dtd)) # breaks ~/.local/lib/python3.6/site-packages/numpy/core/fromnumeric.py in sum(a, axis, dtype, out, keepdims, initial) 2074 2075 return _wrapreduction(a, np.add, 'sum', axis, dtype, out, keepdims=keepdims, -> 2076 initial=initial) 2077 2078 ~/.local/lib/python3.6/site-packages/numpy/core/fromnumeric.py in _wrapreduction(obj, ufunc, method, axis, dtype, out, **kwargs) 84 return reduction(axis=axis, out=out, **passkwargs) 85 ---> 86 return ufunc.reduce(obj, axis, dtype, out, **passkwargs) 87 88 ~/.local/lib/python3.6/site-packages/pandas/core/indexes/base.py in __array_wrap__(self, result, context) 658 attrs = self._get_attributes_dict() 659 attrs = self._maybe_update_attributes(attrs) --> 660 return Index(result, **attrs) 661 662 @cache_readonly ~/.local/lib/python3.6/site-packages/pandas/core/indexes/base.py in __new__(cls, data, dtype, copy, name, fastpath, tupleize_cols, **kwargs) 301 (dtype is not None and is_timedelta64_dtype(dtype))): 302 from pandas.core.indexes.timedeltas import TimedeltaIndex --> 303 result = TimedeltaIndex(data, copy=copy, name=name, **kwargs) 304 if dtype is not None and _o_dtype == dtype: 305 return Index(result.to_pytimedelta(), dtype=_o_dtype) ~/.local/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) 250 251 # check that we are matching freqs --> 252 if verify_integrity and len(data) > 0: 253 if freq is not None and not freq_infer: 254 index = cls._simple_new(data, name=name) TypeError: len() of unsized object