如何通过检测按键来中断Python中的这个循环

Question

from subprocess import call
try:
    while True:
        call (["raspivid -n -b 2666666.67 -t 5000 -o test.mp4"],shell=True)
        call (["raspivid -n -b 2666666.67 -t 5000 -o test1.mp4"],shell=True)
except KeyboardInterrupt:
    pass

我计划让它打破循环，而我正在按任何按钮。然而，我尝试了很多方法来打破这些错误，但没有一种方法奏效。

Answer 1

您希望您的代码更像这样：

from subprocess import call

while True:
    try:
        call(["raspivid -n -b 2666666.67 -t 5000 -o test.mp4"], shell=True)
        call(["raspivid -n -b 2666666.67 -t 5000 -o test1.mp4"], shell=True)
    except KeyboardInterrupt:
        break  # The answer was in the question!

您的break循环与您期望的完全一样。

Answer 2

使用不同的线程来收听"ch“。

import sys
import thread
import tty
import termios
from time import sleep

breakNow = False

def getch():

    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)

    try:
        tty.setraw(sys.stdin.fileno())
        ch = sys.stdin.read(1)
    finally:
        termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)

    return ch

def waitForKeyPress():

    global breakNow

    while True:
        ch = getch()

        if ch == "b": # Or skip this check and just break
            breakNow = True
            break

thread.start_new_thread(waitForKeyPress, ())

print "That moment when I will break away!"

while breakNow == False:
    sys.stdout.write("Do it now!\r\n")
    sleep(1)

print "Finally!"

Answer 3

试试这个：

from subprocess import call
    while True:
        try:
            call (["raspivid -n -b 2666666.67 -t 5000 -o test.mp4"],shell=True)
            call (["raspivid -n -b 2666666.67 -t 5000 -o test1.mp4"],shell=True)
        except KeyboardInterrupt:
            break
        except:
            break