Python将字符串转换为字节

Question

我正在尝试执行一些串行输入和输出操作，其中之一是将8x8阵列发送到外部设备（Arduino）。该pySerial库需要，我发信息是字节。但是，在我的python代码中，8x8矩阵由types组成<class 'str'>。这是我的发送功能：

import serial
import Matrix

width = 8
height = 8
portName = 'COM3'

def sendMatrix(matrix):
    try:
        port = serial.Serial(portName, 9600, timeout = 1000000)
        port.setDTR(0)
        print("Opened port: \"%s\"." % (portName))
        receivedByte = port.read()
        print(int(receivedByte))
        if (receivedByte == '1'):
            port.write('1')
        bytesWritten = 0
        for row in range(8):
            for col in range(8):
                value = matrix.getPoint(col, row)
                bytesWritten += port.write(value)//ERROR HERE!
        print(int(port.read()));
        port.close()
        print("Data (%d) sent to port: \"%s\"." % (bytesWritten, portName))
    except:
        print("Unable to open the port \"%s\"." % (portName))


def main():
    matrix = Matrix.Matrix.readFromFile('framefile', 8, 8)
    matrix.print()
    print(type(matrix.getPoint(0, 0)))
    print(matrix.getPoint(1, 1))
    sendMatrix(matrix)

main()

现在，我有一个类Matrix，其中包含一个field map，这是有问题的数组，我也将在此处包括该代码，但是我遇到的问题是数组中的每个元素都是type str，但是我需要将其转换为字节。我可以忽略可能的数据丢失，因为在实践中，我仅使用0和1。

我的矩阵课：

class Matrix(object):

    def __init__(self, width, height):
        self.width = width
        self.height = height
        self.map = [[0 for x in range(width)] for y in range(height)]

    def setPoint(self, x, y, value):
        if ((x >= 0) and (x < self.width) and (y >= 0) and (y < self.height)):
            self.map[y][x] = value

    def getPoint(self, x, y):
        if ((x >= 0) and (x < self.width) and (y >= 0) and (y < self.height)):
            return self.map[y][x]

    def print(self):
        for row in range(self.height):
            for col in range(self.width):
                print(str(self.map[row][col])+" ", end="")
            print()

    def save(self, filename):
        f = open(filename, 'w')
        for row in range(self.height):
            for col in range(self.width):
                f.write(str(self.map[row][col]))
            f.write('\n')
        f.close()

    def toByteArray(self):
        matrixBytes = bytearray(self.width * self.height)
        for row in range(self.height):
            for col in range(self.width):
                matrixBytes.append(int(self.map[row][col]))
        return matrixBytes

    def getMap(self):
        return self.map

    def readFromFile(filename, width, height):
        f = open(filename, 'r')
        lines = list(f)
        matrix = Matrix(width, height)
        f.close()
        for row in range(len(lines)):
            matrix.map[row] = lines[row].strip('\n')
        return matrix

Answer 1

在 Python 3.x 中，您可以使用如下所示的bytes和str。

>>> bytes('foo'.encode())
b'foo'

>>> a = bytes('foo'.encode())
>>> str(a.decode())
'foo'

Answer 2

要将unicode字符串转换为Python中的字节字符串，请执行以下操作：

>>> 'foo'.encode('utf-8')
b'foo'

要将字节字符串转换为Unicode字符串：

>>> b'foo'.decode('utf-8')
'foo'