使用 sleep 同时运行两个 python 函数

Question

I have two functions but I can't get them to run all the time with the foo() function that sleeps for some time.

import time

filename = "test.dat"

def foo():
    print "It deletes dat file and creates a new one"
    time.sleep(xxx)

def bar():
    print "Writes to dat file"

while True:
    foo()
    bar()

Answer 1

I'm not sure that I correctly understood the problem, but try this one and let me know if that is what you want

import time
from multiprocessing import Process

def foo(x):
    while True:
        print ("It deletes dat file and creates new one")
        time.sleep(x)

def bar():
    while True:
        print ("Wtires to dat file")

process1 = Process(target=foo, args=(0.05,))
process2 = Process(target=bar)
process1.start()
process2.start()

with this code foo() will run with x = 0.05 seconds break and bar() will run all the time... but note that "all the time" means veeeeery often and with no breaks:)

Answer 2

问题是： filename被定义为一个global variable ，一旦foo()删除该文件并创建一个新filename ， filename就变成了一个local variable ，所以bar()函数找不到dat文件，这就是它这样做的原因根本不跑。