decode() missing 1 required positional argument: 'output'

部分代码：

#接受数据：
print(s.recv(1024).decode('utf-8'))

data=s.recv(1024)

def decode_base64(data):
    """Decode base64, padding being optional.

    :param data: Base64 data as an ASCII byte string
    :returns: The decoded byte string.

    """
    missing_padding = len(data) % 4
    if missing_padding != 0:
        data += b'='* (4 - missing_padding)
    return base64.decode(data.decode(encoding='utf-8'))
print (decode_base64(data))

返回信息：

Input command：2015$201520150527103546679209$B101|9011|0|1019909081|1
MCQkMXwxMDE5OTA5MDgxLOmfqeilv+i/niMsRuWMuue/oOWzsOi3r+S4nOaAoeWSjOWutuWbrTXluaIxMjA15a6kLEhCSDAwLDAzLDAuMDAsMC4wMCwwLjAwLDQ5Ljg4
Traceback (most recent call last):
  File "E:\Py\20160809.py", line 36, in <module>
    print (decode_base64(data))
  File "E:\Py\20160809.py", line 35, in decode_base64
    return base64.decode(data.decode(encoding='utf-8'))
TypeError: decode() missing 1 required positional argument: 'output'

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使用 base64.b64decode