Python数据库的学习笔记
SQLite是一个软件库
下面简单介绍一下有关SQLite库的函数
1 | SQLite COUNT 函数 SQLite COUNT 聚集函数是用来计算一个数据库表中的行数。 |
2 | SQLite MAX 函数 SQLite MAX 聚合函数允许我们选择某列的最大值。 |
3 | SQLite MIN 函数 SQLite MIN 聚合函数允许我们选择某列的最小值。 |
4 | SQLite AVG 函数 SQLite AVG 聚合函数计算某列的平均值。 |
5 | SQLite SUM 函数 SQLite SUM 聚合函数允许为一个数值列计算总和。 |
6 | SQLite RANDOM 函数 SQLite RANDOM 函数返回一个介于 -9223372036854775808 和 +9223372036854775807 之间的伪随机整数。 |
7 | SQLite ABS 函数 SQLite ABS 函数返回数值参数的绝对值。 |
8 | SQLite UPPER 函数 SQLite UPPER 函数把字符串转换为大写字母。 |
9 | SQLite LOWER 函数 SQLite LOWER 函数把字符串转换为小写字母。 |
10 | SQLite LENGTH 函数 SQLite LENGTH 函数返回字符串的长度。 |
11 | SQLite sqlite_version 函数 SQLite sqlite_version 函数返回 SQLite 库的版本。 |
承接上次用爬虫获取中国大学排名
代码如下
# -*- coding: utf-8 -*- """ Spyder Editor This is a temporary script file. """ import requests import pandas as pd import numpy as np from bs4 import BeautifulSoup import sqlite3 allUniv=[] def getHTMLText(url): try: r=requests.get(url,timeout=30) r.raise_for_status() r.encoding = 'utf-8' return r.text except: return "" def fillUnivList(soup): data = soup.find_all('tr') for tr in data: ltd = tr.find_all('td') if len(ltd)==0: continue singleUniv = [] for td in ltd: singleUniv.append(td.string) allUniv.append(singleUniv) def printUnivList(num): with open(r'C:UsersDELLDesktop est.txt','w') as f: f.write("{1:^2}{2:{0}^10}{3:{0}^4}{4:{0}^8}{5:{0}^6} ".format((chr(12288)),"排名","学校名称","省市","总分","培训规模")) for i in range(num): u=allUniv[i] f.write("{1:^4}{2:{0}^10}{3:{0}^5}{4:{0}^8.1f}{5:{0}^10} ".format((chr(12288)),u[0],u[1],u[2],eval(u[3]),u[6])) f.close() if 1: print("successful") else: print("fail") def main(num): url='http://www.zuihaodaxue.cn/zuihaodaxuepaiming2018.html' html = getHTMLText(url) soup = BeautifulSoup(html,"html.parser") fillUnivList(soup) printUnivList(num) main(600)
查询我们自己学校的代码为
import requests from bs4 import BeautifulSoup allUniv=[] def getHTMLText(url): try: r=requests.get(url,timeout=30) r.raise_for_status() r.encoding = 'utf-8' return r.text except: return "" def fillUnivList(soup): data = soup.find_all('tr') for tr in data: ltd = tr.find_all('td') if len(ltd)==0: continue singleUniv = [] for td in ltd: singleUniv.append(td.string) allUniv.append(singleUniv) def printUnivList(num): a="广东技术师范学院" print("{1:^4}{2:{0}^8}{3:{0}^6}{4:{0}^6}{5:{0}^8}".format((chr(12288)),"排名","学校名称","省市","总分","培训规模")) for i in range(num): u=allUniv[i] if a in u: print("{1:^4}{2:{0}^10}{3:{0}^5}{4:{0}^8.1f}{5:{0}^10}".format((chr(12288)),u[0],u[1],u[2],eval(u[3]),u[6])) def main(num): url='http://www.zuihaodaxue.cn/zuihaodaxuepaiming2018.html' html = getHTMLText(url) soup = BeautifulSoup(html,"html.parser") fillUnivList(soup) printUnivList(num) main(600)
接着再经过以下代码就可以获得以为科研质量标准的广东大学排名
def printUnivList(num): a="广东技术师范学院" print("{1:^4}{2:{0}^8}{3:{0}^6}{4:{0}^6}{5:{0}^8}".format((chr(12288)),"排名","学校名称","省市","总分","培训规模")) for i in range(num): u=allUniv[i] if a in u: print("{1:^4}{2:{0}^10}{3:{0}^5}{4:{0}^8.1f}{5:{0}^10}".format((chr(12288)),u[0],u[1],u[2],eval(u[3]),u[6]))