Python PySerial：如何理解从串口读取时发生超时？
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原文地址: http://stackoverflow.com/questions/22605164/
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PySerial: how to understand that the timeout occured while reading from serial port?
提问by Konstantin
I'm using PySerialto read from serial port like in the code below.
CheckReadUntil()read output of the command that I send to serial port until the sequence of symbols readUntilare in the serial output.
我正在使用PySerial像下面的代码一样从串行端口读取。
CheckReadUntil()读取我发送到串行端口的命令的输出，直到符号序列readUntil在串行输出中。
...
self.ser = serial.Serial(comDev, 115200, timeout=10)
...
#Function that continue to read from Serial port until 'readUntil'
#sequence of symbols appears
def CheckReadUntil(self, readUntil):
outputCharacters = []
while 1:
ch = self.ser.read()
outputCharacters += ch
if outputCharacters[-len(readUntil):]==readUntil:
break
outputLines = ''.join(outputCharacters)
return outputLines
However, if there is no sequence readUntil(for any reason), I'm just stuck in the function CheckReadUntil()forever. The setting timeout=10sets up timeout so I'm stuck in a loop that iterates every 10 seconds and does nothing, just waiting.
但是，如果没有序列readUntil（出于任何原因），我就会CheckReadUntil()永远停留在函数中。该设置timeout=10设置了超时，所以我陷入了一个循环，每 10 秒迭代一次，什么都不做，只是在等待。
How it is possible to understand that there was a timeout event so I may exit the infinite loop? Output length may be different.
怎么可能理解有一个超时事件，所以我可以退出无限循环？输出长度可能不同。
采纳答案by Fookatchu
UPDATE(previous answer was not correct, this is the working code from @konstantin):
更新（以前的答案不正确，这是@konstantin 的工作代码）：
...
self.ser = serial.Serial(comDev, 115200, timeout=10)
...
#Function that continue to read from Serial port until 'readUntil'
#sequence of symbols appears
def CheckReadUntil(self, readUntil):
outputCharacters = []
while 1:
ch = self.ser.read()
if len(ch) == 0:
break
outputCharacters += ch
if outputCharacters[-len(readUntil):]==readUntil:
break
outputLines = ''.join(outputCharacters)
return outputLines
