import base64s_raw = "中国人a"b_raw = s_raw.encode() # S.encode(encoding='utf-8', errors='strict') -> bytesb64 = base64.b64encode(b_raw)print("b64", b64)s64 = b64.decode()print("s64", s64)b = base64.b64decode(s64)print("b", b)s = b.decode("utf-8") print("s", s)#输出"""b64 b'5Lit5Zu95Lq6YQ=='s64 5Lit5Zu95Lq6YQ==b b'\xe4\xb8\xad\xe5\x9b\xbd\xe4\xba\xbaa's 中国人a"""

b64encode和b64decode接收参数为bytes或ascii码字符串，返回值为bytes。

字符串和bytes互相转换有encode和decode方法，默认编码为utf-8。