Python readline() 返回不会转换为 int 或 float 的字符串 [英] Python readline() returns string that wont convert to int or float

问题描述

我正在使用 Arduino SoftwareSerial 库将串行数据发送到 Raspberry Rx 引脚.我可以成功地将 Arduino 串行数据发送到 Raspberry，因为我发送的整数与字符串中的等效整数一样多.

I am using Arduino SoftwareSerial library to send serial data to a Raspberry Rx pin. I can get the Arduino serial data sent over to the Raspberry successfully, in as much that the integers I sent arrive as the equivalent in a string.

问题:

我正在尝试将 .readline() 返回的字符串转换为 float 或 int，但我无法这样做.

I am trying to convert the string that the .readline() returns into a float or int, but I am unable to do so.

import serial
oSer = serial.Serial("/dev/ttyAMA0",baudrate=57600,timeout=1)

while True:
    sInput = oSer.readline()
    print sInput #Returns: >>1,2,3,

    lsInput = sInput.split(',')
    print lsInput #Returns: >>['1','2','3','\r\n']

如何将其转换为 int 或 float?我只需要对数字做一些算术运算.我试过了:

How can I convert this to an int or float? I simply need to do some arithmetic with the numbers. I have tried:

    lfInput = [float(i) for i in lsInput] #Returns: >> ValueError: could not convert to float:

    liInput = [int(i) for i in lsInput] #Returns: >> ValueError: invalid literal for int() with base 10: ''

答案

感谢提供答案的 John 和 Padraic，我可以确认有关如何解决上述问题的更新.我更喜欢 Padraic 的解决方案，稍微优雅一点，但两者都行.我添加了以下内容:

Thanks to John and Padraic who provided Answers, I can confirm an update on how to fix the above problem. I prefer Padraic's solution, slightly more elegant, but either work. I added the following:

John 的解决方案，尤其是 Pad 的解决方案(有关更好更详细的信息，请参阅下面的答案):

John's and especially Pad's solution (see answers below for better and more detail):

sInput = oSer.readline().strip() #but see answers below from Pad for more detail

推荐答案

该错误是由行尾的 \r\n 引起的.int() 和 float() 不喜欢那样.

The error is caused by the \r\n at the end of the line. int() and float() don't like that.

你可以像这样剥掉它:

sInput = oSer.readline().strip()

或者您可以修改循环以忽略非数字:

Or you can modify the loop to ignore non-numbers:

liInput = [int(i) for i in lsInput if i.isdigit()]

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