Python如何读取16进制byte数据

a = b'\x00\xef\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x19\x39\xd9\x9d\xfdABCDabcd'
b = str(a)
print(b)
>>> b'\x00\xef\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x199\xd9\x9d\xfdABCDabcd'
print(bytes(b,'utf8'))
>>> b"b'\\x00\\xef\\xa2\\xa0\\xb3\\x8b\\x9d\\x1e\\xf8\\x98\\x199\\xd9\\x9d\\xfdABCDabcd'"

# 写入data.txt
a = b'\x00\xef\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x19\x39\xd9\x9d\xfdABCDabcd'
with open('data.txt','w') as p:
    p.write(str(a))
# 读取data.txt
with open('data.txt','r') as p:
    line = p.readline()
print(line, type(line) == str)
>>> b'\x00\xef\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x199\xd9\x9d\xfdABCDabcd\\' True
print(bytes(line,'utf8'))
>>> b"b'\\x00\\xef\\xa2\\xa0\\xb3\\x8b\\x9d\\x1e\\xf8\\x98\\x199\\xd9\\x9d\\xfdABCDabcd\\\\'"

def readbytetxt(filename):
    dic = {
    '0': 0,    '1': 1,    '2': 2,
    '3': 3,    '4': 4,    '5': 5,
    '6': 6,    '7': 7,    '8': 8,
    '9': 9,    'a': 10,   'b': 11,
    'c': 12,   'd': 13,   'e': 14,
    'f': 15,
    with open(filename,'r') as p:
        line = p.readline()
        while line:
            if line[-1] == '\n':
                line = line[:-1]
            i = 2
            L = b''
            while i+1 < len(line):
                if line[i:i+2] == '\\x' and (line[i+2] in dic.keys()) and (line[i+3] in dic.keys()):
                    L += bytes([dic[line[i+2]]*16+dic[line[i+3]]])
                    i += 4
                else:
                    L += bytes(line[i],'utf8')
                    i += 1
            return L
            line = p.readline()
print(readbytetxt('data.txt'))
>>> b'\x00\xef\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x19\x39\xd9\x9d\xfdABCDabcd'

def readbytetxt2(filename):
    dic = {
    '0': 0,    '1': 1,    '2': 2,
    '3': 3,    '4': 4,    '5': 5,
    '6': 6,    '7': 7,    '8': 8,
    '9': 9,    'a': 10,   'b': 11,
    'c': 12,   'd': 13,   'e': 14,
    'f': 15,
    dic2 = {
    'a': '\a',     'b': '\b', 
    'f': '\f',     'n': '\n', 
    'r': '\r',     'v': '\v', 
    '\'': '\'',    '\"': '', 
    '\\': '\\', 
    with open(filename,'r') as p:
        line = p.readline()
        while line:
            if line[-1] == '\n':
                line = line[:-1]
            i = 2
            L = b''
            while i+1 < len(line):
                if line[i:i+2] == '\\x' and (line[i+2] in dic.keys()) and (line[i+3] in dic.keys()):
                    L += bytes([dic[line[i+2]]*16+dic[line[i+3]]])
                    i += 4
                elif line[i] == '\\' and line[i+1] in dic2.keys():
                    L += bytes(dic2[line[i+1]],'utf8')
                    i += 2
                elif line[i:i+4] == '\\000':
                    L += bytes('\000','utf8')
                    i += 2
                else:
                    L += bytes(line[i],'utf8')
                    i += 1
            yield L
            line = p.readline()
a = b'\x00\xef\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x19\x39\xd9\x9d\xfdthe first line\n\r\a\b\t\\\f\'\"\v\b\n\000'
b = b'\xa0\xdf\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x19\x39\xd9\x9d\xfdthe second line\nn'
c = b'\xe0\xaf\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x19\x39\xd9\x9d\xfdthe third line\\'
with open('data.txt','w') as p:
    p.write(str(a)+'\n')
    p.write(str(b)+'\n')
    p.write(str(c))
line = readbytetxt2('data.txt')
print([a for a in line])
>>> [b'\x00\xef\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x199\xd9\x9d\xfdthe first line\n\r\x07\x08\\t\\\x0c\'"\x0b\x08\n\x00', b'\xa0\xdf\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x199\xd9\x9d\xfdthe second line\nn', b'\xe0\xaf\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x199\xd9\x9d\xfdthe third line\\']

L = []
a = b'\x00\xef\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x19\x39\xd9\x9d\xfdthe first line\n\r\a\b\t\\\f\'\"\v\b\n\000'
print(a)
for each in a:
    L.append(int(each))
with open('data.txt','w') as p:
    p.write(str(L))
print(L)
>>> [0, 239, 162, 160, 179, 139, 157, 30, 248, 152, 25, 57, 217, 157, 253, 116, 104, 101, 32, 102, 105, 114, 115, 116, 32, 108, 105, 110, 101, 10, 13, 7, 8, 9, 92, 12, 39, 34, 11, 8, 10, 0]
with open('data.txt','r') as p:
    line = p.readline()
print(b''.join([bytes([int(i)]) for i in line[1:-1].split(',')]))
>>> b'\x00\xef\xa2\xa0\xb3\x8b\x9d\x1e\xf8\x98\x199\xd9\x9d\xfdthe first line\n\r\x07\x08\t\\\x0c\'"\x0b\x08\n\x00'