convert_label_to_indexer.py

import numpy as np

def convert_label_to_indexer(index, label):
    """Given a pandas.Index and labels (e.g., from __getitem__) for one dimension,
    return an indexer suitable for indexing an ndarray along that dimension
    """
    if isinstance(label, slice):
        indexer = index.slice_indexer(label.start, label.stop, label.step)
    elif np.isscalar(label):
        indexer = indexer.get_loc(label)
    else:
        indexer = index.get_indexer(np.asarray(label))
        if np.any(indexer < 0):
            raise ValueError('not all values found in index %r' % dim)    
    return indexer