读书笔记--python数据可视化--005_从数据库导入数据

#-*- coding: UTF-8 -*-
'''
#################################################
# Author : 余欢
# Date : Dec 28, 2015    11:16:49 AM
#company : 南京师范大学--大数据实验室
# description :从数据库导入数据
#################################################
'''
from __builtin__ import str
from _sqlite3 import Row

'''
1  连接数据库引擎(或者SQLite文件)
2  在选择的表上执行查询操作
3  读取从数据库引擎返回的结果
'''
import sqlite3
import sys

#第一步，将SQL文件导入到SQLite数据库中
def ImportDataIntoDB(script_path):
#创建一个数据库
db = "world"

try:
con = sqlite3.connect(db)
with con:
cur = con.cursor()
with open(script_path, "rb") as f:
cur.executescript(f.read())
except sqlite3.Error as e:
print "错误发生：%s" % e

def ReadDataFromDB(db):
try:
con = sqlite3.connect(db)
with con:
cur = con.cursor()
query = "select ID, Name, Population From City Order by Population desc limit 20"
con.text_factory = str
cur.execute(query)

resultset = cur.fetchall()

#提取所有的名称
col_names = [cn[0] for cn in cur.description]
print "%10s %30s %10s" % tuple(col_names)
print "="*(10 + 1 + 30 + 1 + 10)

for row in resultset:
print "%10s %30s %10s" % row
except sqlite3.Error as e:
print "[Error]:", e

if __name__ == "__main__":
ImportDataIntoDB("/root/Desktop/data-visualization/data_visualization_Code/3367OS_02_Code/world.sql")
ReadDataFromDB("world")