小编Aar*_*len的帖子

我有以下几个在多个消费者之间共享的类(使用生产者/消费者方法).我的问题涉及这个类上调用的方法.我需要实现锁定还是经理类线程安全？

import multiprocessing as mp
from multiprocessing.manager import BaseManager

class SampleClass(object):

    def __init__(self):
        self._count = 0

    # Does locking need to be implemented here?
    def increment(self):
        self._count += 1

BaseManager.register('SampleClass', SampleClass)
manager = BaseManager()
manager.start()

instance = manager.SampleClass()

jobs = []
for i in range(0, 5):
    p = mp.Process(target=some_func, args=(instance,))
    jobs.append(p)
    p.start()

for p in jobs:
    p.join()

import re

re.compile(([0-9]|[A-Z0-9]))

这是正确的方法吗？

谢谢!

>>> import ast
>>> string = '[Small, Medium, Large, X-Large]'
>>> print string
[Small, Medium, Large, X-Large]
>>> string = ast.literal_eval(string)
Traceback (most recent call last):  
    File "<pyshell#26>", line 1, in <module>
         string = ast.literal_eval(string)
    File "C:\Python27\lib\ast.py", line 80, in literal_eval
        return _convert(node_or_string)
    File "C:\Python27\lib\ast.py", line 60, in _convert
        return list(map(_convert, node.elts))
  File "C:\Python27\lib\ast.py", line 79, in _convert
    raise ValueError('malformed string')
ValueError: malformed string

怎么修？

import sqlite3    
conn = sqlite3.connect('sample.db')    
cursor = conn.cursor()    
data = cursor.execute('''SELECT * From Table''')

for i in data:    
    title = i[0]        
    status = i[1]    
    cursor.execute('''UPDATED Table SET status=? WHERE title=?''', (status, title))

cursor.close()    
conn.commit()

我正在尝试更新多次迭代.但是,一旦数据库进行第一次更新,脚本就会跳出循环.如何解决这个问题？谢谢!