Python extracts millions of data to a CSV file

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Today there is a need for the system all user registration ID and mailbox and other information exported to provide them, in MySQL count down, about 3.5 million

On the attempt to use Python implementation, incidentally, the function of Python to write CSV, originally wanted to use the tool, but think the next speed will be very slow, the whole export process is about 3 minutes or so, or pretty fast, after all, there are more than 3 million, after the guide is about 150M below is my script deal_csv.py, Because the MySQL database needs to be connected, the script relies on the MySQLdb module?

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__author__ = ‘chunyang.wu‘# -*- coding: utf-8 -*-  #!/usr/bin/env python  import MySQLdb  import os  os.environ[‘NLS_LANG‘] = ‘SIMPLIFIED CHINESE_CHINA.UTF8‘import sys  reload(sys)  sys.setdefaultencoding(‘utf-8‘)  import csv     class Handle:      def __init_db(self):          self._mysql_db = MySQLdb.connect(host="172.16.1.55",user="test",passwd="123456",port=3306,db="test",unix_socket="/tmp/mysql5.sock")          self.mysql_cur=self._mysql_db.cursor()          self.seq = 0      def __init__(self):          self.__init_db()        def _release_db(self):          self.mysql_cur.close()          self._mysql_db.close()         def _do(self):          self.mysql_cur.arraysize = 50        select_sql = "SELECT id,email,FROM_UNIXTIME(create_time) AS create_time FROM test.tbl_member "         print select_sql          self.mysql_cur.execute(select_sql)          count = 0        csvfile = file(‘all_user.csv‘, ‘wb‘)          print dir(csv)          writers = csv.writer(csvfile)          writers.writerow([‘uid‘, ‘email‘, ‘createtime‘])          while 1:              lines = self.mysql_cur.fetchmany(50)              if len(lines)==0:                  break            for i in lines:                  print i                  writers.writerows([i])          csvfile.close()

def main (): P = Handle () p._do () p._release_db () if __name__== "__main__": Main () CSV file structure as

Python extracts millions of data to a CSV file