0 
#!/usr/bin/python 

import time 
from array import *

THINKING  = 0
HUNGRY = 1
EATING = 2

class Philosopher: 
    def __init__(self):
        self.ph = array('i',[1, 2, 3, 4, 5])
        self.sleeptime = array('i',[30, 30, 30, 30, 30])

    def initialization_code(self):
        for i in range(self.ph.__len__()):
            self.ph[i] = THINKING

    def pickup(self,i):
        self.ph[i] = HUNGRY 
        self.test(i)
        if(EATING not in (self.ph[i])):
            while(EATING not in (self.ph[i])):
                time.sleep(self.sleeptime[i])

    def putdown(self,i):
        self.ph[i] = THINKING
        self.test((i+4)%5)
        self.test((i+1)%5)

    def test(self,i):
        if((2 not in (self.ph[(i+4)%5]))and(2 not in (self.ph[(i+1)%5]))and(self.ph[i]==HUNGRY)):
            self.ph[i] = EATING

    def start_process(self):
        for i in range(self.ph.__len__()):
            self.pickup(i)
            self.putdown(i)


    def display_status(self):
        for i in range(self.ph.__len__()):
            if (self.ph[i] == 0):
                print "%d is THINKING" % i+1
            elif (self.ph[i] == 1):
                print "%d is WAITING" % i+1
            elif (self.ph[i] == 2):
                print "%d is EATING" % i+1

phil = Philosopher()
phil.initialization_code()
phil.start_process()
phil.display_status()

以上是我试图在python中实现餐饮哲学家问题的一段代码。当我运行此代码时，它向我显示此错误：

Traceback (most recent call last):

File "dining.py", line 59, in <module>

phil.start_process()

   File "dining.py", line 43, in start_process    
   self.pickup(i)    
   File "dining.py", line 27, in pickup    
   self.test(i)    
   File "dining.py", line 38, in test    
   if((2 not in (self.ph[(i+4)%5]))and(2 not in (self.ph[(i+1)%5]))and(self.ph[i]==HUNGRY)):
   TypeError: argument of type 'int' is not iterable

任何人都可以帮我解决这个问题，为什么会显示此错误。我搜索了它，但无法解决。提前致谢！！

4

3 回答 3

6

你的方程产生整数。你不能in在整数上使用。

>>> 'foo' in 3
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: argument of type 'int' is not iterable
于 2012-06-25T07:04:43.990 回答
2

除了in只能应用于可迭代对象和具有__contains__其类定义的对象的问题之外，您可能会遇到下一个问题：您没有并行化。因此，您应该使用线程或替换

if(EATING not in (self.ph[i])):
    while(EATING not in (self.ph[i])):
        time.sleep(self.sleeptime[i])

行 - 这是一个无限循环，因为没有人设置EATING状态。

或者您应该通过其他方式进行计时，通过不断检查挂钟时间或通过创建一个事件调度系统来处理必须完成的操作。

顺便说一句：print "%d is THINKING" % i+1也被破坏了，因为()周围没有i+1并且%具有更高的优先级。

于 2012-06-25T07:33:56.060 回答
1

我认为您通常使用：

in / not in

不正确。看起来您正在尝试比较应该使用的整数

==
!=
>
>=
<
<=

而是运营商。

于 2012-06-25T07:14:10.383 回答