I don't think so, `mne.read_label()` contains
```python
    if basename.endswith('lh.label') or basename.startswith('lh.'):
        hemi = 'lh'
    elif basename.endswith('rh.label') or basename.startswith('rh.'):
        hemi = 'rh'
    else:
        raise ValueError('Cannot find which hemisphere it is. File should end'
                         ' with lh.label or rh.label')
```
and `Label.__init__()`
```py
        if not isinstance(hemi, string_types):
            raise ValueError('hemi must be a string, not %s' % type(hemi))
```
(wouldn't it make more sense to check it's `in ('lh', 'rh')`?)