def rstrip(a, chars=None):
a_arr = numpy.asarray(a)<EOL>return _vec_string(a_arr, a_arr.dtype, '<STR_LIT>', (chars,))<EOL>
For each element in `a`, return a copy with the trailing
characters removed.

Calls `str.rstrip` element-wise.

Parameters
----------
a : array-like of str or unicode

chars : str or unicode, optional
   The `chars` argument is a string specifying the set of
   characters to be removed. If omitted or None, the `chars`
   argument defaults to removing whitespace. The `chars` argument
   is not a suffix; rather, all combinations of its values are
   stripped.

Returns
-------
out : ndarray
    Output array of str or unicode, depending on input type

See also
--------
str.rstrip

Examples
--------
>>> c = np.array(['aAaAaA', 'abBABba'], dtype='S7'); c
array(['aAaAaA', 'abBABba'],
    dtype='|S7')
>>> np.char.rstrip(c, 'a')
array(['aAaAaA', 'abBABb'],
    dtype='|S7')
>>> np.char.rstrip(c, 'A')
array(['aAaAa', 'abBABba'],
    dtype='|S7')