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这是我用来轮询通过串行端口连接到我的笔记本电脑的 GSM 调制解调器收到的新消息的功能。我创建了一个串行对象“电话”，用于读取和写入数据。

'phone' 将数据读入列表 x。

当我收到一条新消息时，我得到的响应格式如下：

+CMTI: "SM",0

这里0是索引，表示消息在SIM卡上存储的索引位置。以下代码用于轮询列表 x，其中包含我正在从串行端口读取和写入的数据。我正在使用正则表达式来解析已转换为字符串 myRegexableString 的 x 以查看我是否收到通知。

def poll(x):
    myRegexableString = "".join(x)
    print "Printing myRegexableString"
    pprint(myRegexableString)
    regex = re.compile(r'\+CMTI: "SM",(\d+)')
    lst = []
    for l in myRegexableString:
        for m in [regex.search(l)]:
            if myRegexableString:
                lst.append(m)
                print "You have received a new message!"

我想将上述代码用于检查网络注册的 AT 命令。在执行其他命令或任何命令时，我也需要轮询新消息，但为了这个问题，我将举网络注册的例子。以下是它在不使用轮询功能的情况下正常运行的方式。

AT+CREG? #command

+CREG: 0,1 #response

OK #status

现在这是代码。

def register():
   print "Checking for network registration"
   phone.write(b'AT+CREG?\r')
   sleep()
   x=phone.read(50)
   sleep()
   print x

现在假设我在这里包括轮询代码将更改为

def register():
       print "Checking for network registeration"
       phone.write(b'AT+CREG?\r')
       sleep()
       x=phone.read(50)
       poll(x)
       sleep()
       print x

我从更改后的代码中得到的输出是

Checking for network registeration
Printing myRegexableString
'AT+CREG?\r\r\n+CREG: 0,1\r\n\r\nOK\r\n'
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
You have received a new message!
AT+CREG?

+CREG: 0,1

OK

为什么会打印“您收到一条新消息！” 很多次？

特别是当我没有收到新消息时！

请帮忙。

4

1 回答 1

1

您需要做的就是使用regex.findall(myRegexableString). 这将返回匹配组的列表，即数字。

regex = re.compile(r'\+CMTI: "SM",(\d+)')

def poll(x):
    myRegexableString = "".join(x)
    print "Printing myRegexableString"
    pprint(myRegexableString)
    lst = regex.findall(myRegexableString)

I've moved the re.compile() call out of the function, there is no need to re-compile the expression every time.

You are looping over each and every character of myRegexableString, then you loop over a list with one match, then you test if myRegexableString is True-ish (which it is if it is not empty). This means that for every character in the input you add an empty match (the expression will never match anything in a single character string).

于 2013-03-29T11:21:10.540 回答