如何停止无限循环并继续使用其余代码?

时间:2017-06-14 20:37:27

标签: python while-loop raspbian raspberry-pi3

问题是我无法在不停止整个程序的情况下退出while循环。

当我在Raspberry Pi上执行代码时,相机开始录制,但是当我想结束视频并按Ctrl + c时,整个程序会在while循环后停止而不是继续。我认为信号处理程序会捕获键盘中断,但事实并非如此。

我的代码:

import picamera
import signal
from time import sleep
from subprocess import call

def signal_handler(signal, frame):
        global interrupted
        interrupted = True

signal.signal(signal.SIGINT, signal_handler)

interrupted = False

# Setup the camera
with picamera.PiCamera() as camera:
    camera.resolution = (1640, 922)
    camera.framerate = 30

    # Start recording
    camera.start_recording("pythonVideo.h264")

while True:
        sleep(0.5)
        print("still recording")

        if interrupted:
                print("Ctrl+C pressed")
                camera.stop_recording()
                break

# Stop recording
#camera.stop_recording()

# The camera is now closed.

print("We are going to convert the video.")
# Define the command we want to execute.
command = "MP4Box -add pythonVideo.h264 convertedVideo.mp4 -fps 30"
#Execute command.
call([command], shell=True)
# Video converted.
print("Video converted.")

我尝试了什么:

bflag = True
while bflag ==True:
        sleep(0.5)
        print("still recording")

        if interrupted:
                print("Ctrl+C pressed")
                camera.stop_recording()
                bflag = False

错误:

pi@raspberrypi:~/Documents/useThisFolder $ python cookieVideo.py 
still recording
still recording
still recording
still recording
still recording
^Cstill recording
Ctrl+C pressed
Traceback (most recent call last):
  File "cookieVideo.py", line 29, in <module>
    camera.stop_recording()
  File "/usr/lib/python2.7/dist-packages/picamera/camera.py", line 1193, in stop_recording
'port %d' % splitter_port)
picamera.exc.PiCameraNotRecording: There is no recording in progress on port 1

2 个答案:

答案 0 :(得分:4)

这样就可以了:

while True:
    try:
        sleep(0.5)
        print("still recording")
    except KeyboardInterrupt:
        print("Ctrl+C pressed")
        camera.stop_recording()
        break

答案 1 :(得分:-1)

enter image description here

正如您所看到的,它与@ mdurant的代码完美配合。