python - 从if [Python]退出

Question

如果构造我不能退出

#!/usr/bin/python2.7
import os
import re
import time
global state


#print status_on.group()
def main():
    get_current_jack_status = """amixer -c1 contents | grep -A 2 'Headphone Jack'"""
    output = os.popen(get_current_jack_status).read()
    status_on = re.search('values=on', output)
    if status_on:
        state = status_on
        os.system("notify-send 'Audio Manager' 'An audio jack was plugged in' -i audacity.png")
        if status_on == state:
            print "True"
            state = 1   #here i can't exit

        if status_on != state:
            print state
            os.system("notify-send 'Audio Manager' 'An audio jack was unplugged' -i audacity.png")


while True:
    main()

我尝试通过，但是当我执行脚本时，它显示为输出:

True
1
True
1

等
如果我使用“break”，它将崩溃。

Answer 1

这应该工作。将全局声明移到main函数内部，然后这将初始化状态，然后检查状态更改。这可能可以清除一点(即if语句)，但它应该可以工作。

#!/usr/bin/python2.7
import os
import sys
import re
import time


#print status_on.group()
def main():
    global state
    get_current_jack_status = """amixer -c1 contents | grep -A 2 'Headphone Jack'"""
    output = os.popen(get_current_jack_status).read()
    status_on = re.search('values=on', output)
    if (status_on is None and state) or (state is None and status_on):
        state = status_on
        if status_on:
            print "a jack was plugged in"
            os.system("notify-send 'Audio Manager' 'An audio jack was plugged in' -i audacity.png")
        else:
            print "a jack was unplugged"
            os.system("notify-send 'Audio Manager' 'An audio jack was unplugged' -i audacity.png")

get_current_jack_status = """amixer -c1 contents | grep -A 2 'Headphone Jack'"""
output = os.popen(get_current_jack_status).read()
state = re.search('values=on', output)

while True:
        main()