Python_报错：SyntaxError: unexpected character after line continuation character

>>> import os
>>> os.makedirs(time_year+"\\"+time_month+"\\"+time_day)#其中的time_year、time_month、time_day都是有赋值的变量
>>> os.chdir(time_year\time_month\time_day)#问题出在这里，写法不对
  File "<stdin>", line 1
    os.chdir(time_year\time_month\time_day)
                                          ^
SyntaxError: unexpected character after line continuation character

>>> os.chdir(time_year+"\\"+time_month+"\\"+time_day)#正确的
>>> with open(time_hours+".txt","w+") as fp:#此种方法能正常进入下一步操作
...     fp.read()
...