Return an array with the elements converted to uppercase.
Calls str.upper element-wise.
For 8-bit strings, this method is locale-dependent.
| Parameters : | a : array_like, {str, unicode} 
  | 
|---|---|
| Returns : | out : ndarray, {str, unicode} 
  | 
See also
Examples
>>> c = np.array(['a1b c', '1bca', 'bca1']); c
array(['a1b c', '1bca', 'bca1'],
    dtype='|S5')
>>> np.char.upper(c)
array(['A1B C', '1BCA', 'BCA1'],
    dtype='|S5')