python3 encode decode base64

python3 base64时需要byte类型，encode默认编码为utf-8，decode默认将utf-8解码成我们能看懂的字符

>>> a = base64.b64encode('中'.encode())>>> ab'5Lit'>>> type(a)<class 'bytes'>>>> b = base64.b64encode('中'.encode()).decode()>>> b'5Lit'>>> type(b)<class 'str'>>>> type('中')<class 'str'>>>> c = base64.b64decode(a)>>> cb'\xe4\xb8\xad'>>> type(c)<class 'bytes'>>>> c = base64.b64decode(a).decode()>>> c'中'>>> type(c)<class 'str'>>>> '中'.encode()b'\xe4\xb8\xad'>>>