python 爬虫 多线程用queue做队列，消费者线程无法从ｑｕｅｕｅ中取出数据。

Answer 1

消费者join一下试试，然后你判断一下条件，如果queue为空的时候，循环break

Answer 2

如果self.Queue为空的话, self.Queue.get() 会抛出 Queue.Empty 异常，这时候线程会退出，这时候都没有工作线程了。
在run()方法的while循环里面增加try...except捕获该异常试试。代码大概如下：

while True:
    try:
       self.Queue.get(timeout=5) #这里的timeout可以根据情况设置为合适的值
    except Queue.Empty:  # 任务队列空的时候结束此线程
        break
    except:
        raise
        

=======================================================================
首先：对于你说的mysql不支持多线程写入问题，我简单写了个验证程序，结论是mysql支持多线程写入的(注：实际工作中在多线程中往db中写入数据，需要加入锁机制，这里简化了)，代码如下：

#coding: utf-8

import MySQLdb
import MySQLdb.cursors
import threading

class MySql(object):
    def __init__(self, host, user, pwd, db_name, port=3306):
        self.host = host
        self.user = user
        self.pwd = pwd
        self.db_name = db_name
        self.port = port
        self.conn = None
        self.cursor = None
        self.connect()

    def connect(self):
        try:
            self.conn = MySQLdb.connect(host=self.host, user=self.user, passwd=self.pwd, db=self.db_name,
                                        port=self.port)
            self.cursor = self.conn.cursor(cursorclass=MySQLdb.cursors.DictCursor)
        except Exception, err:
            print 'connect: %s' % err
        return self.conn
            
    def execute(self, sql):
        rs = ()
        try:
            self.cursor.execute(sql)
            rs = self.cursor.fetchall()
        except Exception, err:
            pass
        return rs

    def exec_and_result(self, sql):
        ret_id = -1
        try:
            self.cursor.execute(sql)
            self.conn.commit()
            ret_id = self.cursor.lastrowid
        except Exception, err:
            print 'exec_and_result: %s' % err
        return ret_id

    def close(self):
        try:
            self.cursor.close()
            self.conn.close()
        except Exception, err:
            pass

db = {
    'ip': 'xxx.xxx.xxx.xxx',
    'port': xxx,
    'user': 'xxx',
    'pwd': 'xxx',
    'db_name': 'xxx'
}             
mysql = MySql(db['ip'], db['user'], db['pwd'], db['db_name'], int(db['port']))
threads = []

def do(name):
    sql = "insert into site(name, status, create_time, update_time, update_user_account, comment) values('{0}', 0, NOW(), NOW(), 'daiyapeng', 'test');"
    rid = mysql.exec_and_result(sql.format(name))
    print rid

for i in ['test-0'，'test-1'，'test-2']:
    t = threading.Thread(target=do, args=(i, ))
    threads.append(t)

for t in threads:
    t.start()

for t in threads:
    t.join()
            
mysql.close()
            
            
            

另外：因为不清楚你的代码的具体细节，所以不能完全定位问题，我自己写了个模拟程序，没有出现你的那种情况，希望对你有帮助，代码如下：

#coding: utf-8

import Queue
import threading

class MyThread(threading.Thread):
    def __init__(self, queue):
        threading.Thread.__init__(self)
        self.setDaemon(True)
        self.queue = queue

    def run(self):
        while True:
            try:
                task = self.queue.get(timeout=2)
                print 'task: %s' % task
                # 这里可以处理task
            except Exception, err:
                break

if __name__ == '__main__':
    threads = []
    q = Queue.Queue()
    for i in xrange(3):
        thread = MyThread(q)
        threads.append(thread)

    for t in threads:
        t.start()

    for i in xrange(30):
        q.put(i)
    
    for t in threads:
        t.join()

    print '====== done ======'