字节数组 ->字符串

bytes.decode()

a = bytes([0x30, 0x31, 0x32, 0x33])
b = a.decode('ascii')
print(b)
# 输出结果
# 0123

字符串 -> 字节数组

str.encode('utf-8')

import binascii
a = '0123'
b = a.encode('ascii')
print(binascii.hexlify(b))
# 输出结果
# b'30313233'

可变字节数组 -> 字符串

bytes和string类型一样为不可变类型，bytes对应的可变类型为bytearray

a = bytearray([0x30, 0x31, 0x32, 0x33])
a.append(0x34)
a.append(0x35)
b = a.decode('ascii')
print(b)
# 输出内容
# 012345