code: def p_expr_ternary_op(p):
      'expr : expr QUESTION expr COLON expr'
      p[0] = ast.TernaryOp(p[1], p[3], p[5], lineno=p.lineno(2)f p_expr_ternary_op(p):
      'expr : expr QUESTION expr COLON expr'
      p[0] = ast.TernaryOp(p[1], p[3], p[5], lineno=p.lineno(2))
docs: expr : expr QUESTION expr COLON expr