函数打印“等待”，同时等待另一个函数的值。
函数打印“等待”，同时等待另一个函数的值。
提问于 2014-04-14 18:08:19
如何在函数receive不发送args的情况下对print "waiting"执行print "waiting"函数？
嗯，我真的不知道怎么做，我想到了join()方法，但我尝试了如下：
import threading
import random
waiting = True
def receive(a=""):
while waiting:
print "[receive] waiting for args"
print "[receive] Args received: %s" % a # args received from send function
def send(args):
global waiting
if waiting:
if random.randint(1,3) == 2:
waiting = False
print "[send] Args sent"
receive(a=args) # send the args
fargs = ["hello, world", "foo", "bar", "foobar", 12]
t1 = threading.Thread(target=receive, args=[])
t2 = threading.Thread(target=send, args=[fargs])
t1.start()
t2.start()有时这是可行的，但有时我会陷入无限的循环。
@编辑
现在它工作得很好：
import threading
import random
waiting = True
def receive(a=""):
while waiting:
print "[receive] waiting for args"
if a:
print "[receive] Args received: %s" % a
def send(args):
global waiting
while waiting:
if random.randint(1,3) == 2:
waiting = False
print "[send] Args sent"
receive(a=args)
fargs = ["hello, world", "foo", "bar", "foobar", 12]
t1 = threading.Thread(target=receive, args=[])
t2 = threading.Thread(target=send, args=[fargs])
t1.start()
t2.start()有更好的方法吗？
对不起我的英语。
回答 1
Stack Overflow用户
发布于 2017-03-26 10:36:31
我知道这个线程很旧，但是通过OP对self答案进行扩展，我创建了一个类，在运行给定函数时打印一个字符串。
import threading
import queue
import time
import getpass
class DotsPrinter:
def __init__(self, float_dots_frequency=1,
string_to_print_while_waiting="."):
self.float_dots_frequency = float_dots_frequency
self.string_to_print_while_waiting = string_to_print_while_waiting
self.bool_waiting = True
self.output_queue = queue.Queue()
def print_dots(self):
if self.bool_waiting:
print("Waiting ", end="", flush=True)
while self.bool_waiting:
print(self.string_to_print_while_waiting, end="",
flush=True)
time.sleep(self.float_dots_frequency)
def function_wrapper(self, function, *args, **kwargs):
self.output_queue.put(function(*args, **kwargs))
self.bool_waiting = False
def print_dots_while_executing(self, function, *args, **kwargs):
t1 = threading.Thread(target=self.print_dots)
t2 = threading.Thread(target=self.function_wrapper, args=
[function, *args], kwargs={**kwargs})
t1.start()
t2.start()
return self.output_queue.get()使用非常简单：
def count_till_timeout(timeout):
start_time = time.time()
n = 0
while time.time() - start_time < timeout:
n += 1
return n
n = DotsPrinter().print_dots_while_executing(count_till_timeout, 5)
print(n)我没有对它进行外部测试，所以它可能有一些but，而且我也不是线程方面的专家，因此我不知道是否应该这样做，但我希望它能帮助到别人。我用它打印点，而熊猫从sql DB下载数据。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/23067101
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