def get_one(self, section, key):
lines = iter(self.get(section, key))<EOL>try:<EOL><INDENT>return next(lines)<EOL><DEDENT>except StopIteration:<EOL><INDENT>raise KeyError("<STR_LIT>" % (key, section))<EOL><DEDENT>
Retrieve the first value for a section/key.

        Raises:
            KeyError: If no line match the given section/key.