python如何捕获中断

Question

我目前有一个爬虫, 爬取的东西目测要好些天才能完

所以我设计成了能够自动续爬的形式, 不过我选择想再进一步

记录每次开始和结束的时间

但是不知道怎样在<ctrl-C>这种键盘终端的时候去写下程序退出的时间

望指点指点, 感觉是要捕获异常..

Answer 1

catch KeyboardInterrupt

import time
import datetime

print('stime:', datetime.datetime.now())
try:
    while True:
        time.sleep(1)
        print('go')
except KeyboardInterrupt:
    print('etime:', datetime.datetime.now())

測試:

stime: 2016-07-28 01:54:21.647561
go
go
go
<Ctrl+c>
etime: 2016-07-28 01:54:25.010312

---

我回答過的問題: Python-QA

Answer 2

那就捕信号吧，ctrl-c也是信号，SIGINT

man kill:
Some of the more commonly used signals:
     1       HUP (hang up)
     2       INT (interrupt)
     3       QUIT (quit)
     6       ABRT (abort)
     9       KILL (non-catchable, non-ignorable kill)
     14      ALRM (alarm clock)
     15      TERM (software termination signal)

import time
import signal

def CtrlCHandler(signum, frame):
    current_time = time.time()
    sys.exit(0)

signal.signal(signal.SIGINT, CtrlCHandler)

Ctrl-C 或者 kill -2 pid的时候都会到这个CtrlCHandler.

建议用信号而不是KeyboardInterrupt

Answer 3

Ctrl+C 会产生KeyboardInterrupt异常,捕获它就可以了

try:
   #要执行的代码
except KeyboardInterrupt, e:
    print "Interrupt..."