如何在串行控制台的字符串上使用pyserial Expect，然后发送字符

Question

I'm a new to python, hoping someone knows something about the issue I have. I want to control a device using serial console. A command will be sent to reboot the device, while the device is rebooting, a string is printed. I want to catch the string and then send a character "h" which will abort the reboot. Code looks like this

#! /bin/env python

import serial
import sys
import pexpect
from time import sleep
from serial import SerialException

ser = serial.Serial()
ser.baudrate = 9600
ser.port="/dev/ttyUSB0"
ser.stopbits=serial.STOPBITS_ONE
ser.xonxoff=0

try:
    ser.open()
except:
    sys.exit ("Error opening port")

print "Serial port opened"
ser.write('rebootnow\r')

temp = ser.expect('press h now to abort reboot..')

if i == 0:
    print ('Gotcha, pressing h')
    ser.sendline('h')
    print ('Reboot aborted')
else:
    print ('Ouch, got nothing')
    time.sleep(1)
ser.close()

exit()

When I run the code, I get the error

AttributeError: 'Serial' object has no attribute 'expect'

at line

temp = ser.expect('press h now to abort reboot..')

Any ideas?

Answer 1

This thread is quite old, but I hope my answer can still be useful to you.

The expect methods are from pexpect, not from pyserial. You should do something like:

temp = pexpect.fdpexpect.fdspawn(ser)
temp.expect("message")

Basically, from temp onwards you should call methods on the temp object, not on the serial object. This includes the sendline() call, later on.