扭曲线接收不到被称为 [英] Twisted lineReceived not getting called

问题描述

我在python中构建命令行界面时遇到了一个奇怪的行为.这是可以重现此问题的代码的简化版本.

I encountered a strange behavior when i was building a command line interface in python. Here is the striped down version of the code that can reproduce the issue.

from twisted.internet import reactor, stdio
from twisted.protocols import basic

class CommandLine(basic.LineReceiver):
    def __init__(self):
        self.linebuf = ''
        self.setLineMode()

    # why lineReceived  doesn't work?
    # def lineReceived(self, data):
    def dataReceived(self, data):
        print 'data received ' + ' '.join([str(ord(c)) for c in data ])
        print data


if __name__=='__main__':
    stdio.StandardIO(CommandLine())
    reactor.run()

上面的代码按预期工作，每次输入一行时，都会以接收到的数据108 115 115 10"的形式输出.这是使用dataReceived的示例输出:

The code above works as intended, out put in the form of "data received 108 115 115 10" is printed everytime a line is entered. Here is a sample output using dataReceived:

$ python cmdline.py
hello
data received 104 101 108 108 111 10
hello

^[[A
data received 27 91 65 10

但是，当我使用lineReceived而不是上面的代码中的dataReceived时，除了命令行本身的回显之外，什么都没有打印出来.使用lineReceived的示例输出:

However nothing gets printed out except the echo of the command line itself when I use lineReceived instead of dataReceived in the code above. Example output using lineReceived:

$ python cmdline.py
hello
^[[A

根据 lineReceived ，当LineReceiver以行模式接收到一行时，将调用lineReceived函数.

According the the documentation on lineReceived, the lineReceived function gets invoked when a line is received with the LineReceiver in line mode.

目前，我正在使用dataReceived使其工作.但是我想找出为什么lineReceived不能按预期工作.任何提示，建议和建议，将不胜感激！

For now I am using dataReceived to make it work. But I would like to find out why lineReceived is not working as intended. Any hint, suggestions, advice would be very much appreciated!

致谢.

推荐答案

原因是定界符常量，默认情况下设置为r'\ r \ n'(MS Windows定界符).尝试将其设置为"\ n"(Linux和Mac OS):

The reason is line delimiter constant which is set to r'\r\n' by default (MS Windows delimiter). Try to set it to '\n' (Linux and Mac OS) instead:

class CommandLine(basic.LineReceiver):
    delimiter = '\n'

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