def expr(self, values, offset=<NUM_LIT:0>):
if isinstance(values, dict):<EOL><INDENT>for name in values:<EOL><INDENT>if not self.has_variable(name):<EOL><INDENT>raise ValueError('<STR_LIT>'.format(name))<EOL><DEDENT><DEDENT>return Expression(values, offset=offset)<EOL><DEDENT>if not self.has_variable(values):<EOL><INDENT>raise ValueError('<STR_LIT>'.format(values))<EOL><DEDENT>return Expression({values: <NUM_LIT:1>}, offset=offset)<EOL>
Return the given dictionary of values as an :class:`.Expression`.