numpy的"float64"对象没有属性"translate"，在Python中将值插入到MySQL中

Question

import dataset
db = dataset.connect(....)
table = db[...]

当我试图在Mysql表中插入一些值时，发生了这个错误。

我要插入到表中的示例值：

print("Buy", ticker, price, date, OType, OSize)
Buy AAPL 93.4357142857 2016-05-12 Market 200
data = dict(Order_Side='Buy',Ticker=ticker, Price=price, 
                            Order_Date= date, Order_Type = OType, Volume = OSize )
table.insert(data)

错误消息：

Traceback (most recent call last):

  File "<ipython-input-3-b7ab0c98f72f>", line 1, in <module>
    runfile('C:/Users/SwigelUser/Documents/GitHub/Trading/Strategies/strat_MA_ExecTest.py', wdir='C:/Users/SwigelUser/Documents/GitHub/Trading/Strategies')

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 880, in runfile
    execfile(filename, namespace)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 102, in execfile
    exec(compile(f.read(), filename, 'exec'), namespace)

  File "C:/Users/SwigelUser/Documents/GitHub/Trading/Strategies/strat_MA_ExecTest.py", line 69, in <module>
    MA_Stra(start_length=7,end_length=10,start_date=date(2016,5,12),end_date=date(2016,6,18))

  File "C:/Users/SwigelUser/Documents/GitHub/Trading/Strategies/strat_MA_ExecTest.py", line 66, in MA_Stra
    table.insert(data1)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\dataset\persistence\table.py", line 87, in insert
    res = self.database.executable.execute(self.table.insert(row))

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\sqlalchemy\engine\base.py", line 945, in execute
    return meth(self, multiparams, params)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\sqlalchemy\sql\elements.py", line 263, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\sqlalchemy\engine\base.py", line 1053, in _execute_clauseelement
    compiled_sql, distilled_params

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\sqlalchemy\engine\base.py", line 1189, in _execute_context
    context)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\sqlalchemy\engine\base.py", line 1405, in _handle_dbapi_exception
    util.reraise(*exc_info)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\sqlalchemy\util\compat.py", line 187, in reraise
    raise value

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\sqlalchemy\engine\base.py", line 1182, in _execute_context
    context)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\sqlalchemy\engine\default.py", line 470, in do_execute
    cursor.execute(statement, parameters)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\pymysql\cursors.py", line 164, in execute
    query = self.mogrify(query, args)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\pymysql\cursors.py", line 143, in mogrify
    query = query % self._escape_args(args, conn)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\pymysql\cursors.py", line 123, in _escape_args
    return dict((key, conn.literal(val)) for (key, val) in args.items())

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\pymysql\cursors.py", line 123, in <genexpr>
    return dict((key, conn.literal(val)) for (key, val) in args.items())

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\pymysql\connections.py", line 821, in literal
    return self.escape(obj, self.encoders)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\pymysql\connections.py", line 814, in escape
    return escape_item(obj, self.charset, mapping=mapping)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\pymysql\converters.py", line 27, in escape_item
    val = encoder(val, mapping)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\pymysql\converters.py", line 110, in escape_unicode
    return u"'%s'" % _escape_unicode(value)

  File "C:\Users\SwigelUser\Anaconda3\lib\site-packages\pymysql\converters.py", line 73, in _escape_unicode
    return value.translate(_escape_table)

AttributeError: 'numpy.float64' object has no attribute 'translate'

是什么导致了这个错误？我怎么能解决这个问题。 似乎我在这里输入了太多的代码，因此我将不得不键入许多毫无意义的代码才能提交。

我的价格和日期变量来自一个数据框：

for i in range(len(All_Tickers)-1-len(Current_Date),len(All_Tickers)-1):
    price = All_Tickers[str(length) + 'day_MA'][i]
    date = All_Tickers['Date'][i+1]

根据下面的答案，问题应该是价格类型是np.float64，我如何将这个变量转换为float类型？

Answer 1

在建立pymysql连接之前，将下面的命令添加到任意位置。它添加了新的numpy.float64编码器。

pymysql.converters.encoders[np.float64] = pymysql.converters.escape_float
pymysql.converters.conversions = pymysql.converters.encoders.copy()
pymysql.converters.conversions.update(pymysql.converters.decoders)