# numpy.char.index

char.index(a, sub, start=0, end=None)

  Like `find`, but raises ValueError when the substring is not found.

  Calls str.index element-wise.

  Parameters:
    a array_like of str or unicode
    sub str or unicode
    start, end int, optional
  Returns:
    out ndarray

      Output array of ints. Returns -1 if sub is not found.

  See also

  `find`, `str.find`

  Examples

      >>> a = np.array(["Computer Science"])
      >>> np.char.index(a, "Science", start=0, end=None)
      array([9])