n [1]: import pandas as pd In [2]: mi = pd.MultiIndex(labels = [[1.25, 0.25, 3.1], [3.2, 1.2, 4.1]], levels=[['a'], ['a', 'b', 'c']]) In [3]: mi Out[3]: MultiIndex(levels=[[u'a'], [u'a', u'b', u'c']], labels=[[1, 0, 3], [3, 1, 4]]) In [4]: mi.values --------------------------------------------------------------------------- IndexError Traceback (most recent call last) <ipython-input-4-e9591d864c48> in <module>() ----> 1 mi.values /Users/jtratner/projects/python/pandas/pandas/core/index.py in values(self) 2163 values = [] 2164 for lev, lab in zip(self.levels, self.labels): -> 2165 taken = com.take_1d(lev.values, lab) 2166 # Need to box timestamps, etc. 2167 if hasattr(lev, '_box_values'): /Users/jtratner/projects/python/pandas/pandas/core/common.py in take_nd(arr, indexer, axis, out, fill_value, mask_info, allow_fill) 630 func = _get_take_nd_function(arr.ndim, arr.dtype, out.dtype, 631 axis=axis, mask_info=mask_info) --> 632 func(arr, indexer, out, fill_value) 633 return out 634 /Users/jtratner/projects/python/pandas/pandas/algos.so in pandas.algos.take_1d_object_object (pandas/algos.c:68489)() IndexError: Out of bounds on buffer access (axis 0) In [5]: mi Out[5]: MultiIndex(levels=[[u'a'], [u'a', u'b', u'c']], labels=[[1, 0, 3], [3, 1, 4]]) In [6]: mi.levels Out[6]: FrozenList([[u'a'], [u'a', u'b', u'c']]) In [7]: mi.labels Out[7]: FrozenList([[1, 0, 3], [3, 1, 4]])