在 python 中使用队列

问题描述

我正在尝试在 Eclipse(使用 PyDev)中运行以下命令，但我不断收到错误消息:

q = queue.Queue(maxsize=0)NameError:未定义全局名称队列"

我已经检查了文档，看起来应该是这样放置的.我在这里错过了什么吗?PyDev 是这样工作的吗?或在代码中遗漏了什么?感谢大家的帮助.

从队列导入 *定义工人():而真:项目 = q.get()做工作(项目)q.task_done()定义主():q = queue.Queue(maxsize=0)对于我在范围内(num_worker_threads):t = 线程(目标 = 工人)t.daemon = 真t.start()对于 source() 中的项目:q.put(项目)q.join() # 阻塞直到所有任务完成主要的()

使用:Eclipse SDK

版本:3.8.1内部版本号:M20120914-1540

和 Python 3.3

解决方案

你做

从队列导入 *

这已经从 queue 模块中导入了所有类.将该行更改为

q = 队列(maxsize=0)

<块引用>

小心:应避免通配符导入(来自 import *)，因为它们使命名空间中存在哪些名称变得不清楚，从而使读者和许多自动化工具感到困惑".(Python PEP-8)

作为一种替代方法，可以使用:

从队列导入队列q = 队列(最大尺寸=0)

I'm trying to run the following in Eclipse (using PyDev) and I keep getting error :

q = queue.Queue(maxsize=0) NameError: global name 'queue' is not defined

I've checked the documentations and appears that is how its supposed to be placed. Am I missing something here? Is it how PyDev works? or missing something in the code? Thanks for all help.

from queue import *

def worker():
    while True:
        item = q.get()
        do_work(item)
        q.task_done()

def main():

    q = queue.Queue(maxsize=0)
    for i in range(num_worker_threads):
         t = Thread(target=worker)
         t.daemon = True
         t.start()

    for item in source():
        q.put(item)

    q.join()       # block until all tasks are done

main()

Using: Eclipse SDK

Version: 3.8.1 Build id: M20120914-1540

and Python 3.3

解决方案

You do

from queue import *

This imports all the classes from the queue module already. Change that line to

q = Queue(maxsize=0)

CAREFUL: "Wildcard imports (from import *) should be avoided, as they make it unclear which names are present in the namespace, confusing both readers and many automated tools". (Python PEP-8)

As an alternative, one could use:

from queue import Queue

q = Queue(maxsize=0)