如何让 python Parallel 与本地 mysql 服务器一起工作？

Question

如何让 python Parallel 与本地 mysql 服务器一起工作？

Dar*_*311 3 python mysql parallel-processing

我正在尝试将一堆插入并行化到 mysql。所有数据库服务器设置看起来都已准备好用于大量连接和/或线程。下面添加了完整的代码和完整的错误消息。谷歌搜索最终的错误消息没有返回任何相关内容：

操作错误：（2006，“MySQL 服务器已消失”）

Code:
> #!/usr/bin/python
# -*- coding: utf-8 -*-

# price_retrieval.py

from __future__ import print_function

import datetime
import warnings

import MySQLdb as mdb
import requests
from joblib import Parallel, delayed
import multiprocessing

# Obtain a database connection to the MySQL instance
db_host = 'localhost'
db_user = 'sec_user'
db_pass = 'password'
db_name = 'securities_master'
con = mdb.connect(db_host, db_user, db_pass, db_name)


def obtain_list_of_db_tickers():
   """
   Obtains a list of the ticker symbols in the database.
   """
   with con:
       cur = con.cursor()
       cur.execute("SELECT id, ticker FROM symbol")
       data = cur.fetchall()
       return [(d[0], d[1]) for d in data]


def is_db_current():
   # check that database is loaded up to yesterday's details or the last trading day.
   # ??? is there an app for last trading day. # holidays could trip up schedule.
   # nothing is currently designed for same day data.
   sql = "select max(price_date), symbol_id, ticker \
       from securities_master.daily_price left join securities_master.symbol \
       on  securities_master.daily_price.symbol_id =  securities_master.symbol.id \
       group by symbol_id limit 5"
#
   today = datetime.date.today().weekday()
   data = None
   with con:
       cur = con.cursor()
       cur.execute(sql)
       data = cur.fetchall()
   tuples = [(d[0], d[1], d[2]) for d in data]

   # if data is upto yesterday return true
   # elsif data is current up to friday return true
   # so if friday is filled and it's sat or sun or mon return true.
   # Monday = 0 Sunday = 6
   for t in tuples:
       if abs(today - t[0].weekday()) <= 1:
           #good but keep looping.
           continue
       elif today in [5,6,0]  and t[0].weekday() == 4:
           #good but keey looping.
           continue
       else:
           return False
       # made it through checks so
   return True
#        datetime.utcnow().dayofweek

def get_daily_historic_data_yahoo(
       ticker, start_date=(2000,1,1),
       end_date=datetime.date.today().timetuple()[0:3]
   ):
   """
   Obtains data from Yahoo Finance returns and a list of tuples.

   ticker: Yahoo Finance ticker symbol, e.g. "GOOG" for Google, Inc.
   start_date: Start date in (YYYY, M, D) format
   end_date: End date in (YYYY, M, D) format
   """
   # Construct the Yahoo URL with the correct integer query parameters
   # for start and end dates. Note that some parameters are zero-based!
   ticker_tup = (
       ticker, start_date[1]-1, start_date[2],
       start_date[0], end_date[1]-1, end_date[2],
       end_date[0]
   )
   yahoo_url = "http://ichart.finance.yahoo.com/table.csv"
   yahoo_url += "?s=%s&a=%s&b=%s&c=%s&d=%s&e=%s&f=%s"
   yahoo_url = yahoo_url % ticker_tup

   # Try connecting to Yahoo Finance and obtaining the data
   # On failure, print an error message.
   try:
       yf_data = requests.get(yahoo_url).text.split("\n")[1:-1]
       prices = []
       for y in yf_data:
           p = y.strip().split(',')
           prices.append(
               (datetime.datetime.strptime(p[0], '%Y-%m-%d'),
               p[1], p[2], p[3], p[4], p[5], p[6])
           )
   except Exception as e:
       print("Could not download Yahoo data: %s" % e)
   return prices

def get_daily_historid_data_google():
   prices = []
   return prices

def insert_daily_data_into_db(
       data_vendor_id, symbol_id, daily_data
   ):
   """
   Takes a list of tuples of daily data and adds it to the
   MySQL database. Appends the vendor ID and symbol ID to the data.

   daily_data: List of tuples of the OHLC data (with
   adj_close and volume)
   """
   # Create the time now
   now = datetime.datetime.utcnow()

   # Amend the data to include the vendor ID and symbol ID
   daily_data = [
       (data_vendor_id, symbol_id, d[0], now, now,
       d[1], d[2], d[3], d[4], d[5], d[6])
       for d in daily_data
   ]

   # Create the insert strings
   column_str = """data_vendor_id, symbol_id, price_date, created_date,
                last_updated_date, open_price, high_price, low_price,
                close_price, volume, adj_close_price"""
   insert_str = ("%s, " * 11)[:-2]
   final_str = "INSERT IGNORE INTO daily_price (%s) VALUES (%s)" % \
       (column_str, insert_str)

   # Using the MySQL connection, carry out an INSERT INTO for every symbol
   with con:
       cur = con.cursor()
       cur.executemany(final_str, daily_data)

def load_ticker_history(t):
   print( "Adding data for %s" % (t[1]) )
   yf_data = get_daily_historic_data_yahoo(t[1], (2015,01,01))
   insert_daily_data_into_db('1', t[0], yf_data)


if __name__ == "__main__":
   # This ignores the warnings regarding Data Truncation
   # from the Yahoo precision to Decimal(19,4) datatypes
   warnings.filterwarnings('ignore')

   # Loop over the tickers and insert the daily historical
   # data into the database
   tickers = obtain_list_of_db_tickers()
   lentickers = len(tickers)
   num_cores = multiprocessing.cpu_count()
   print("numCores = " + str(num_cores))

   if is_db_current():
       print("db current: True")
   else:
       # not sure why
       Parallel(n_jobs=1)(delayed(load_ticker_history)(t) for t in tickers)
       print("Successfully added Yahoo Finance pricing data to DB.")

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错误

输出：

/usr/bin/python /Users/darianhickman/Documents/Quantstart/src/dev/price_retrieval.py numCores = 2 添加 A 数据添加 AA 数据添加 AAL 数据添加 AAP 数据添加 AAPL 数据添加 ABBV 数据添加ABC 的数据添加 ABT 的数据添加 ACE 的数据添加 ACN 的数据添加 ADBE 的数据添加 ADI 的数据添加 ADM 的数据添加 ADP 的数据添加 ADS 的数据添加 ADSK 的数据添加 ADT 的数据添加 AEE 的数据添加 AEE 的数据AEP 添加 AES 数据添加 AET 数据添加 AFL 数据添加 AGN 数据添加 AIG 数据添加 AIV 数据添加 AIZ 数据添加 AKAM 数据添加 ALL 数据添加 ALLE 数据添加 ALTR Traceback 数据（最近调用）最后）：文件“/Users/darianhickman/Documents/Quantstart/src/dev/price_retrieval.py”，第 164 行，并行（n_jobs=2）（延迟（load_ticker_history）（t） for t in 股票）文件“/Library /Python/2.7/site-packages/joblib/parallel.py”，第 660 行，在调用 self.retrieve() 文件“/Library/Python/2.7/site-packages/joblib/parallel.py”，第 543 行，在检索引发异常类型（报告） joblib.my_exceptions.JoblibOperationalError：JoblibOperationalError ___________________________________________________________________________ 多处理异常：................................ ......................................... /Users/darianhickman/Documents/Quantstart /src/dev/price_retrieval.py in () 159 print("numCores = " + str(num_cores)) 160 161 如果不是 is_db_current(): 162 print("db current: True") 163 else: --> 164 并行(n_jobs=2)(delayed(load_ticker_history)(t) for t in tickers) 165 print("成功将雅虎财经定价数据添加到数据库。") 166 167 168

...................................................... ......................... /Library/Python/2.7/site-packages/joblib/parallel.py 调用中(self=Parallel(n_jobs= 2), iterable=>) 655 if pre_dispatch == "all" or n_jobs == 1: 656 # iterable 被上面的 for 循环一次性消耗掉了。657 # 无需等待异步回调触发即可消费。 658 # 消费。659 self._iteating = False --> 660 self.retrieve() self.retrieve = 661 # 确保我们收到最后一条消息，告诉我们已经完成 662 elapsed_time = time.time() - self._start_time 663 self._print ('已完成 %3i，共 %3i | 已完成：%s 已完成', 664 (len(self._output),
---------------------------------------------------------------------------
Sub-process traceback:
---------------------------------------------------------------------------
OperationalError                                   Fri Sep 11 22:42:58 2015 PID: 39551                                   Python
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2.7.10: /usr/bin/python ................................................ ................................... /Users/darianhickman/Documents/Quantstart/src/dev/price_retrieval。 py in load_ticker_history(t=(17L, 'AKAM')) 141 cur.executemany(final_str, daily_data) 142 143 def load_ticker_history(t): 144 print( "为 %s 添加数据" % (t[1]) ) 145 yf_data = get_daily_historic_data_yahoo(t[1], (2015,01,01)) --> 146 insert_daily_data_into_db('1', t[0], yf_data) t = (17L, 'AKAM') yf_data = [(datetime.datetime (2015, 9, 11, 0, 0), u'74.32', u'75.32', u'73.940002', u'74.669998', u'1368400', u'74.669998'), (datetime.datetime(2015, 9, 10, 0, 0), u'73.279999', u'75.029999', u'73.190002', u'74.550003', u'1408900', u'74.550003'), (datetime.datetime(2015, 9, 9) , 0, 0), u'74.879997', u'75.25', u'73.129997', u'73.349998', u'1273300', u'73.349998'), (datetime.datetime(2015, 9, 8, 0, 0), u'73.75', u'74.349998', u'73.059998', u'74.279999', u'1413600', u'74.279999'), (datetime.datetime(2015, 9, 4, 0, 0), u'71.709999', u'73.169998', u'71.709999', u'72.580002', u'1607100', u'72.580002'), (datetime.datetime(2015, 9, 3, 0, 0), u'71.860001 ', u'74.709999', u'71.540001', u'73.260002', u'2378600', u'73.260002'), (datetime.datetime(2015, 9, 2, 0, 0), u'71.349998', u '71.669998', u'69.669998', u'71.269997', u'1671900', u'71.269997'), (datetime.datetime(2015, 9, 1, 0, 0), u'69.75', u'71.43' , u'69.669998', u'70.43', u'2401800', u'70.43'), (datetime.datetime(2015, 8, 31, 0, 0), u'71.660004', u'71.809998', u' 70.870003', u'71.309998', u'1764400', u'71.309998'), (datetime.datetime(2015, 8, 28, 0, 0), u'70.589996', u'71.970001', u'70.199997', u'71.900002', u'2371800', u'71.900002'), (datetime.datetime(2015, 8, 27, 0, 0), u'69.089996', u'70.889999', u'68.529999', u'70.50 ', u'2081800', u'70.50'), (datetime.datetime(2015, 8, 26, 0, 0), u'67.07', u'68.300003', u'65.330002', u'68.169998', u '2238400', u'68.169998'), (datetime.datetime(2015, 8, 25, 0, 0), u'68.239998', u'68.989998', u'65.589996', u'65.629997', u'3112100' , u'65.629997'), (datetime.datetime(2015, 8, 24, 0, 0), u'65.010002', u'68.220001', u'63.139999', u'66.519997', u'3779300', u' 66.519997'), (日期时间.日期时间(2015,8, 21, 0, 0), u'69.190002', u'70.00', u'67.910004', u'68.040001', u'2298300', u'68.040001'), (datetime.datetime(2015, 8, 20) , 0, 0), u'72.300003', u'72.57', u'69.769997', u'69.779999', u'2096000', u'69.779999'), (datetime.datetime(2015, 8, 19, 0, 0), u'73.779999', u'73.900002', u'72.290001', u'73.059998', u'881700', u'73.059998'), (datetime.datetime(2015, 8, 18, 0, 0), u'73.959999', u'74.190002', u'73.230003', u'73.849998', u'1220500', u'73.849998'), (datetime.datetime(2015, 8, 17, 0, 0), u'73.010002 ', u'73.599998', u'72.32', u'73.57', u'1025600', u'73.57'), (datetime.datetime(2015, 8, 14, 0, 0), u'73.379997', u '73.839996'，u'72.730003'，u'73.370003'，u'1328400'，u'73.370003')，...] 147 148 149 如果name == " main ": 150 # 这会忽略有关数据截断的警告

...................................................... ......................... /Users/darianhickman/Documents/Quantstart/src/dev/price_retrieval.py in insert_daily_data_into_db(data_vendor_id='1', symbol_id=17L, daily_data=[('1', 17L, datetime.datetime(2015, 9, 11, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), 日期时间。日期时间(2015,9,12,2,42,58,361925),u'74.32',u'75.32',u'73.940002',u'74.669998',u'1368400',u'74.669998'),(' 1', 17L, datetime.datetime(2015, 9, 10, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2) , 42, 58, 361925), u'73.279999', u'75.029999', u'73.190002', u'74.550003', u'1408900', u'74.550003'), ('1', 17L, datetime.datetime( 2015, 9, 9, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u '74.879997', u'75.25', u'73.129997', u'73.349998', u'1273300', u'73.349998'), ('1', 17L, datetime.datetime(2015, 9, 8, 0, 0) ), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'73.75', u'74.349998', u'73.059998', u'74.279999', u'1413600', u'74.279999'), ('1', 17L, datetime.datetime(2015, 9, 4, 0, 0), datetime.datetime(2015, 9 , 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'71.709999', u'73.169998', u'71.709999', u'72.580002' , u'1607100', u'72.580002'), ('1', 17L, datetime.datetime(2015, 9, 3, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'71.860001', u'74.709999', u'71.540001', u'73.260002', u'2378600', u'73.260002 '), ('1', 17L, datetime.datetime(2015, 9, 2, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'71.349998', u'71.669998', u'69.669998', u'71.269997', u'1671900', u'71.269997'), ('1', 17L , datetime.datetime(2015, 9, 1, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58) , 361925), u'69.75', u'71.43', u'69.669998', u'70.43', u'2401800', u'70.43'), ('1', 17L, datetime.datetime(2015, 8, 31, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'71.660004', u'71.809998', u'70.870003', u'71.309998', u'1764400', u'71.309998'), ('1', 17L, datetime.datetime(2015, 8, 28, 0, 0), 日期时间。日期时间(2015,9,12,2,42,58,361925),日期时间。日期时间(2015,9,12,2,42,58,361925),u'70.589996',u'71.970001',u'70.199997',u'71.900002',u'2371800',u'71.900002'),(' 1', 17L, datetime.datetime(2015, 8, 27, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2) , 42, 58, 361925), u'69.089996', u'70.889999', u'68.529999', u'70.50', u'2081800', u'70.50'), ('1', 17L, datetime.datetime( 2015, 8, 26, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u '67.07', u'68.300003', u'65.330002', u'68.169998', u'2238400', u'68.169998'), ('1', 17L, datetime.datetime(2015, 8, 25, 0, 0) ), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'68.239998', u'68.989998', u'65.589996', u'65.629997', u'3112100', u'65.629997'), ('1', 17L, datetime.datetime(2015, 8, 24, 0, 0), datetime.datetime(2015, 9 , 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'65.010002', u'68.220001', u'63.139999', u'66.519997' , u'3779300', u'66.519997'), ('1', 17L, datetime.datetime(2015, 8, 21, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'69.190002', u'70.00', u'67.910004', u'68.040001', u'2298300', u'68.040001 '), ('1', 17L, datetime.datetime(2015, 8, 20, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'72.300003', u'72.57', u'69.769997', u'69.779999', u'2096000', u'69.779999'), ('1', 17L , datetime.datetime(2015, 8, 19, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58) , 361925), u'73.779999', u'73.900002', u'72.290001', u'73.059998', u'881700', u'73.059998'), ('1', 17L, datetime.datetime(2015, 8, 18, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'73.959999', u'74.190002'、u'73.230003'、u'73.849998'、u'1220500'、u'73.849998')、('1'、17L、datetime.datetime(2015,8,17,0,0),日期时间。日期时间(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'73.010002', u'73.599998', u'72.32' , u'73.57', u'1025600', u'73.57'), ('1', 17L, datetime.datetime(2015, 8, 14, 0, 0), datetime.datetime(2015, 9, 12, 2 , 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'73.379997', u'73.839996', u'72.730003', u'73.370003', u'1328400', u'73.370003'), ...]) 136 (column_str, insert_str) 137 138 # 使用MySQL连接，执行对每个带有 con 的符号 139 进行 INSERT INTO： 140 cur = con.cursor() --> 141 cur.executemany(final_str, daily_data) cur.executemany => Final_str = 'INSERT IGNORE INTO daily_price (data_vendor_id, ...LUES ( %s、%s、%s、%s、%s、%s、%s、%s、%s、%s、%s)' daily_data = [('1', 17L, datetime.datetime(2015, 9, 11, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'74.32 ', u'75.32', u'73.940002', u'74.669998', u'1368400', u'74.669998'), ('1', 17L, datetime.datetime(2015, 9, 10, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'73.279999', u'75.029999', u' 73.190002', u'74.550003', u'1408900', u'74.550003'), ('1', 17L, datetime.datetime(2015, 9, 9, 0, 0), datetime.datetime(2015, 9, 12 , 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'74.879997', u'75.25', u'73.129997', u'73.349998', u '1273300', u'73.349998'), ('1', 17L, datetime.datetime(2015, 9, 8, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925) , datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'73.75', u'74.349998', u'73.059998', u'74.279999', u'1413600', u'74.279999') , ('1', 17L, datetime.datetime(2015, 9, 4, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'71.709999', u'73.169998', u'71.709999', u'72.580002', u'1607100', u'72.580002'), ('1', 17L, 日期时间.datetime(2015, 9, 3, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925 ), u'71.860001', u'74.709999', u'71.540001', u'73.260002', u'2378600', u'73.260002'), ('1', 17L, datetime.datetime(2015, 9, 2, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'71.349998', u' 71.669998', u'69.669998', u'71.269997', u'1671900', u'71.269997'), ('1', 17L, datetime.datetime(2015, 9, 1, 0, 0), datetime.datetime( 2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'69.75', u'71.43', u'69.669998', u '70.43', u'2401800', u'70.43'), ('1', 17L, datetime.datetime(2015, 8, 31, 0, 0), 日期时间。日期时间(2015,9,12,2,42,58,361925),datetime.datetime(2015,9,12,2,42,58,361925),u'71.660004',u'71.809998',u'70.870003' , u'71.309998', u'1764400', u'71.309998'), ('1', 17L, datetime.datetime(2015, 8, 28, 0, 0), datetime.datetime(2015, 9, 12, 2 , 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'70.589996', u'71.970001', u'70.199997', u'71.900002', u'2371800 ', u'71.900002'), ('1', 17L, datetime.datetime(2015, 8, 27, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime .datetime(2015,9,12,2,42,58,361925),u'69.089996',u'70.889999',u'68.529999',u'70.50',u'2081800',u'70.50'),( '1', 17L, datetime.datetime(2015, 8, 26, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'67.07', u'68.300003', u'65.330002', u'68.169998', u'2238400', u'68.169998'), ('1', 17L, 日期时间.日期时间(2015, 8, 25, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'68.239998', u'68.989998', u'65.589996', u'65.629997', u'3112100', u'65.629997'), ('1', 17L, datetime.datetime(2015, 8, 24, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'65.010002', u'68.220001' , u'63.139999', u'66.519997', u'3779300', u'66.519997'), ('1', 17L, datetime.datetime(2015, 8, 21, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'69.190002', u'70.00', u'67.910004', u'68.040001 ', u'2298300', u'68.040001'), ('1', 17L, datetime.datetime(2015, 8, 20, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58 , 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'72.300003', u'72.57', u'69.769997', u'69.779999', u'2096000', u' 69.779999'), ('1', 17L, datetime.datetime(2015, 8, 19, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015) , 9, 12, 2, 42, 58, 361925), u'73.779999', u'73.900002', u'72.290001', u'73.059998', u'881700', u'73.059998'), ('1', 17L, datetime.datetime(2015, 8, 18, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925), u'73.959999', u'74.190002', u'73.230003', u'73.849998', u'1220500', u'73.849998'), ('1', 17L, datetime.datetime(2015, 8) , 17, 0, 0), datetime.datetime(2015, 9, 12, 2, 42, 58, 361925),datetime.datetime(2

Answer 1

pat*_*cus 5

MySQL 连接不是线程安全的。当多个进程尝试使用同一连接时，可能会发生此错误。

确保每个并行进程创建和销毁自己的数据库连接。

来自MySQL 文档：

对于派生子进程的应用程序，所有这些子进程都尝试使用与 MySQL 服务器的相同连接，您也可能会遇到此错误。通过为每个子进程使用单独的连接可以避免这种情况。

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