读源码1

def reindex(self, *args, **kwargs): # construct the args axes, kwargs = self._construct_axes_from_arguments(args, kwargs) method = missing.clean_reindex_fill_method(kwargs.pop('method', None)) ''' 下面的代码，最是精妙 ''' level = kwargs.pop('level', None) copy = kwargs.pop('copy', True) limit = kwargs.pop('limit', None) tolerance = kwargs.pop('tolerance', None) fill_value = kwargs.pop('fill_value', np.nan) if kwargs: raise TypeError('reindex() got an unexpected keyword ' 'argument "{0}"'.format(list(kwargs.keys())[0])) self._consolidate_inplace() # if all axes that are requested to reindex are equal, then only copy # if indicated must have index names equal here as well as values if all([self._get_axis(axis).identical(ax) for axis, ax in axes.items() if ax is not None]): if copy: return self.copy() return self # check if we are a multi reindex if self._needs_reindex_multi(axes, method, level): try: return self._reindex_multi(axes, copy, fill_value) except: pass # perform the reindex on the axes return self._reindex_axes(axes, level, limit, tolerance, method, fill_value, copy).__finalize__(self)