def open(self):
if self._f is not None:<EOL><INDENT>return self._f<EOL><DEDENT>try:<EOL><INDENT>rv, self.should_close = open_stream(self.name, self.mode,<EOL>self.encoding,<EOL>self.errors,<EOL>atomic=self.atomic)<EOL><DEDENT>except (IOError, OSError) as e:<EOL><INDENT>from .exceptions import FileError<EOL>raise FileError(self.name, hint=get_streerror(e))<EOL><DEDENT>self._f = rv<EOL>return rv<EOL>
Opens the file if it's not yet open.  This call might fail with
        a :exc:`FileError`.  Not handling this error will produce an error
        that Click shows.