python - 计算我访问某个线程的次数

Question

我有以下代码来计算我访问线程的次数。代码运行良好，但我想知道是否可以在不涉及任何全局变量的情况下实现。

import threading
import lib.logging
import time

count = 0

class Monitor(threading.Thread):
    def __init__(self, count):
        threading.Thread.__init__(self)

    def run(self):
        global count
        count+=1
        lib.logging.debug ("Count is: " + str(count))

def main():        
    for i in xrange(3): 
        t1 = Monitor(count)
        t2 = Monitor(count)   
        t1.start()
        t2.start()
        t1.join()
        t2.join()
        time.sleep(3)

    print "done"

非常感谢

Answer 1

可以使用itertools.count和Python的函数默认参数行为来计算没有全局变量的函数调用:

import threading
import lib.logging
import time
from itertools import count


class Monitor(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)

    def run(self, count=count()):
        # next(count) starts from 0, so to log first '1', + 1 is used
        lib.logging.debug ("Count is: " + str(next(count) + 1))

def main():        
    for i in xrange(3): 
        t1 = Monitor()
        t2 = Monitor()   
        t1.start()
        t2.start()
        t1.join()
        t2.join()
        time.sleep(3)

    print "done"

这是一篇关于 python 函数默认参数的文章:http://www.lexev.org/en/2013/python-mutable-default-arguments/