Update QR204 class

class QR204(object):
	_printer = None
	CODEPAGE = {
		"CHINESE":255,
		"BIG5":254,
		"UTF-8":253,
		"SHIFT-JIS":252,
		"EUC-KR":251,
		"CP437":0,
		"Katakana":1,
		"CP850":2,
		"CP860":3,
		"CP863":4,
		"CP865":5,
		"CP1251":6,
		"CP866":7,
		"MIK":8,
		"CP755":9,
		"Iran":10,
		"CP862":15,
		"CP1252":16,
		"CP1253":17,
		"CP852":18,
		"CP858":19,
		"Iran II":20,
		"Latvian":21,
		"CP864":22,
		"ISO-8859-1":23,
		"CP737":24,
		"CP1257":25,
		"Thai":26,
		"CP720":27,
		"CP855":28,
		"CP857":29,
		"CP1250":30,
		"CP775":31,
		"CP1254":32,
		"CP1255":33,
		"CP1256":34,
		"CP1258":35,
		"ISO-8859-2":36,
		"ISO-8859-3":37,
		"ISO-8859-4":38,
		"ISO-8859-5":39,
		"ISO-8859-6":40,
		"ISO-8859-7":41,
		"ISO-8859-8":42,
		"ISO-8859-9":43,
		"ISO-8859-15":44,
		"Thai2":45,
		"CP856":46,
		"Cp874":47,
	}
	def __init__(self, uart):
		self._printer = uart
		self._printer.write(b'\x03\xFF\x20\x00\x00\x00\x00\x00\x08\x00\xD4\x18DEVICE??')
		self._printer.read(12)
		self.model = self._printer.read(8)
		self.config()
		self._printer.write(b'\x1b\x40')
		self._printer.write(b'\x1b\x37')
		self._printer.write(b'\x14\x96\x50')
		self._printer.write(b'\x12\x23\xff')
	def test(self):
		self.write("\x12\x54")
	def setpage(self, codepage="UTF-8"):
		self.codepage = codepage
		self._printer.write(b'\x1bt%c'%self.CODEPAGE[codepage])
	def config(self, codepage="UTF-8", baud=9600, sn="000000"):
		self.codepage = codepage
		sn = int(sn,16)
		cfg =b'\x00\x00%c%c%c%c%c%c'%(
			baud//256,baud%256,
			self.CODEPAGE[codepage],
			(sn>>16)%256,(sn>>8)%256,sn%256)
		s = 0
		for x in cfg:
			s = s^x
		self._printer.write(b'\x03\xFF\x60\x00\x00\x00\x00\x00\x08\x00\x94%c%s'%(s,cfg))
		return self._printer.read(12)
	def newline(self, n=3):
		self._printer.write(b'\x0a' * n)
	def inverse_enbl(self):
		self._printer.write(b'\x1d\x42\x01')
	def inverse_dsbl(self):
		self._printer.write(b'\x1d\x42\x00')
	def bold_enbl(self):
		self._printer.write(b'\x1b\x45\x01')
	def bold_dsbl(self):
		self._printer.write(b'\x1b\x45\x00')
	def font_b(self):
		self._printer.write(b'\x1b\x21\x01')
	def font_a(self):
		self._printer.write(b'\x1b\x21\x00')
	def font_size(self,w,h):
		self._printer.write(b'\x1d\x21%c'%((w*16+h%16)%256))
	def uline_enbl(self):
		self._printer.write(b'\x1b\x2d\x01')
	def uline_dsbl(self):
		self._printer.write(b'\x1b\x2d\x00')
	def align(self, arg='<'):
		if '<' in arg:
			self._printer.write(b'\x1b\x61\x00')
		elif '>' in arg:
			self._printer.write(b'\x1b\x61\x02')
		else:
			self._printer.write(b'\x1b\x61\x01')
	def write(self, text):
		self._printer.write(bytes(text,self.codepage))
	def writeln(self, text):
		self.write(text+'\n')

'''Example
printer = QR204(port)
printer.uline_enbl()
printer.write('Underline')
printer.uline_dsbl()
printer.newline(1)
printer.bold_enbl()
printer.write('Bold')
printer.bold_dsbl()
printer.newline(1)
printer.inverse_enbl()
printer.write('Inverse')
printer.inverse_dsbl()
printer.newline(1)
printer.font_b()
printer.write('Font B')
printer.font_a()
printer.newline(3)
'''

Добавил настройку кодировки, скорости связи и установку размеров шрифта. так как тестил на компе с питоном 3 то записал отправку строк как bytes(text,self.codepage)
вот тут выложил https://gist.github.com/NeiroNx/df26db4afafa9801e66d92fdbc49990d