Question

python新手学习语法中，求解下面的错误错在哪。

class Hotdog:
def __init__(self):
self.cooked_level=0
self.cooked_string='raw'
self.cooked_condiments=[]

def cook(self,time):
self.cooked_level=self.cooked_level+time
if self.cooked_level>8:
self.cooked_string='Charcoal'
elif self.cooked_level>5:
self.cooked_string='Well-done'
elif self.cooked_level>3:
self.cooked_string='Raw'

def __str__(self):
msg="Now the hot dog cooked level is "+str(self.cooked_level)
msg1="The hot dog cooked string is "+self.cooked_string
return msg,msg1

my_hotdog=Hotdog()

my_hotdog.cook(4)
print my_hotdog

运行以后返回的错误信息是

Traceback (most recent call last):
File "E:/python2.5/作业文件/烤热狗，对象问题", line 24, in <module>
print my_hotdog
TypeError: __str__ returned non-string (type tuple)

Answer 1

__str__这个函数必须返回字符串类型，而你现在返回的是元组。