读取mysql数据库中一列，并换行写入到文件中

# coding=gbk
from pymysql import *


def deal():
    conn = connect(host='***', port=3306, database='***', user='***',
                   password='***', charset='utf8')
    cs1 = conn.cursor()
    cs1.execute("SELECT 字段名 from 表名")
    pnlist = []
    alldata = cs1.fetchall()
    for singl_company in alldata:
        pnlist.append(singl_company[0])
    cs1.close()
    conn.close()
    try:
        fp = open('需要写入的文件路径', "w+")
        for item in pnlist:
            fp.write(str(item) + "\n")  # 一条记录占一行
        fp.close()
    except IOError:
        print("fail to open file")


if __name__ == '__main__':
    deal()