class clean_string:

    def __init__(self,cadena):
        self.replace_chars = {"á":"a","ó":"o"}
        self.cadena = cadena
    def split_func(self):
        return self.cadena.split(' ')

python3 clean.py

$ python clean.py
  File "clean.py", line 4
SyntaxError: Non-ASCII character 'xc3' in file clean.py on line 4, but no encoding declared; see http://python.org/dev/peps/pep-0263/ for details