爬虫好学么？5 行代码就可以

import pandas as pd
import csv
for i in range(1,178):  # 爬取全部页
	tb = pd.read_html('http://s.askci.com/stock/a/?reportTime=2017-12-31&pageNum=%s' % (str(i)))[3] 
	tb.to_csv(r'1.csv', mode='a', encoding='utf_8_sig', header=1, index=0)

import requests
import pandas as pd
from bs4 import BeautifulSoup
from lxml import etree
import time
import pymysql
from sqlalchemy import create_engine
from urllib.parse import urlencode  # 编码 URL 字符串

start_time = time.time()  #计算程序运行时间
def get_one_page(i):
	try:
		headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36'
        }
		paras = {
		'reportTime': '2017-12-31',
		#可以改报告日期，比如2018-6-30获得的就是该季度的信息
		'pageNum': i   #页码
		}
		url = 'http://s.askci.com/stock/a/?' + urlencode(paras)
		response = requests.get(url,headers = headers)
		if response.status_code == 200:
			return response.text
		return None
	except RequestException:
		print('爬取失败')

def parse_one_page(html):
	soup = BeautifulSoup(html,'lxml')
	content = soup.select('#myTable04')[0] #[0]将返回的list改为bs4类型
	tbl = pd.read_html(content.prettify(),header = 0)[0]
	# prettify()优化代码,[0]从pd.read_html返回的list中提取出DataFrame
	tbl.rename(columns = {'序号':'serial_number', '股票代码':'stock_code', '股票简称':'stock_abbre', '公司名称':'company_name', '省份':'province', '城市':'city', '主营业务收入(201712)':'main_bussiness_income', '净利润(201712)':'net_profit', '员工人数':'employees', '上市日期':'listing_date', '招股书':'zhaogushu', '公司财报':'financial_report', '行业分类':'industry_classification', '产品类型':'industry_type', '主营业务':'main_business'},inplace = True)
	return tbl

def generate_mysql():
	conn = pymysql.connect(
		host='localhost',
		user='root',
		password='******',
		port=3306,
		charset = 'utf8',  
		db = 'wade')
	cursor = conn.cursor()

	sql = 'CREATE TABLE IF NOT EXISTS listed_company (serial_number INT(20) NOT NULL,stock_code INT(20) ,stock_abbre VARCHAR(20) ,company_name VARCHAR(20) ,province VARCHAR(20) ,city VARCHAR(20) ,main_bussiness_income VARCHAR(20) ,net_profit VARCHAR(20) ,employees INT(20) ,listing_date DATETIME(0) ,zhaogushu VARCHAR(20) ,financial_report VARCHAR(20) , industry_classification VARCHAR(20) ,industry_type VARCHAR(100) ,main_business VARCHAR(200) ,PRIMARY KEY (serial_number))'
	cursor.execute(sql)
	conn.close()
	
def write_to_sql(tbl, db = 'wade'):
    engine = create_engine('mysql+pymysql://root:******@localhost:3306/{0}?charset=utf8'.format(db))
    try:
    	tbl.to_sql('listed_company2',con = engine,if_exists='append',index=False)
    	# append表示在原有表基础上增加，但该表要有表头
    except Exception as e:
    	print(e)

def main(page):
    generate_mysql()
	for i in range(1,page):  
		html = get_one_page(i)
		tbl = parse_one_page(html)
		write_to_sql(tbl)
		
# # 单进程
if __name__ == '__main__':	
	main(178)
	endtime = time.time()-start_time
	print('程序运行了%.2f秒' %endtime)
	
# 多进程
from multiprocessing import Pool
if __name__ == '__main__':
 	pool = Pool(4)
 	pool.map(main, [i for i in range(1,178)])  #共有178页
	endtime = time.time()-start_time
	print('程序运行了%.2f秒' %(time.time()-start_time))