我正在编写一个python脚本，启动几个进程和数据库连接。有时我想用Ctrl+C信号终止脚本，我想做一些清理工作。
在Perl中，我会这样做:
$SIG{'INT'} = 'exit_gracefully';
sub exit_gracefully {
print "Caught ^C \n";
exit (0);
}
如何在Python中进行类似操作?
当前回答
你可以像对待其他异常一样对待它(KeyboardInterrupt)。创建一个新文件，并在shell中运行它，包含以下内容，看看我的意思:
import time, sys
x = 1
while True:
try:
print x
time.sleep(.3)
x += 1
except KeyboardInterrupt:
print "Bye"
sys.exit()
其他回答
你可以像对待其他异常一样对待它(KeyboardInterrupt)。创建一个新文件，并在shell中运行它，包含以下内容，看看我的意思:
import time, sys
x = 1
while True:
try:
print x
time.sleep(.3)
x += 1
except KeyboardInterrupt:
print "Bye"
sys.exit()
作为一个上下文管理器:
import signal
class GracefulInterruptHandler(object):
def __init__(self, sig=signal.SIGINT):
self.sig = sig
def __enter__(self):
self.interrupted = False
self.released = False
self.original_handler = signal.getsignal(self.sig)
def handler(signum, frame):
self.release()
self.interrupted = True
signal.signal(self.sig, handler)
return self
def __exit__(self, type, value, tb):
self.release()
def release(self):
if self.released:
return False
signal.signal(self.sig, self.original_handler)
self.released = True
return True
使用方法:
with GracefulInterruptHandler() as h:
for i in xrange(1000):
print "..."
time.sleep(1)
if h.interrupted:
print "interrupted!"
time.sleep(2)
break
嵌套的处理程序:
with GracefulInterruptHandler() as h1:
while True:
print "(1)..."
time.sleep(1)
with GracefulInterruptHandler() as h2:
while True:
print "\t(2)..."
time.sleep(1)
if h2.interrupted:
print "\t(2) interrupted!"
time.sleep(2)
break
if h1.interrupted:
print "(1) interrupted!"
time.sleep(2)
break
网址:https://gist.github.com/2907502
你可以通过捕获KeyboardInterrupt异常来处理CTRL+C。您可以在异常处理程序中实现任何清理代码。
用signal注册你的处理程序。信号是这样的:
#!/usr/bin/env python
import signal
import sys
def signal_handler(sig, frame):
print('You pressed Ctrl+C!')
sys.exit(0)
signal.signal(signal.SIGINT, signal_handler)
print('Press Ctrl+C')
signal.pause()
代码改编自这里。
更多关于信号的文档可以在这里找到。
另一个片段
将main作为main函数，将exit_elegant作为Ctrl+C处理程序
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
pass
finally:
exit_gracefully()
