初試Python爬蟲下載pdf
阿新 • • 發佈:2019-01-26
最近剛學完Boyd的Convex Optimization,真是對Boyd神佩服得五體投地。在他的lecture slides末尾發現原來還有進階課程Stanford的ee364b,那本convex optimization只包括了ee364a,然而ee364b沒有現成的完整slides一次性下載,只好寫個爬蟲挨個下載儲存slides,在ee364b裡的內容更加專業深入,估計實際很少用到。然後我把爬蟲的程式碼貼上來,還好他們的網頁結構比較簡單,程式碼量不大。下載好的檔案裡有些是空白的,回網站一查發現確實是他們沒有在裡面留東西,就這樣吧。
import requests import re import os from bs4 import BeautifulSoup def GetPage(url): page = requests.get(url) html = page.text return html def GetList(html): soup = BeautifulSoup(html, "html5lib") list = soup.find_all(href=re.compile("lectures/")) pdfs = [] for li in list: if (li.get('href'))[-4:] == ".pdf": pdfs.append(li.get('href')) return pdfs def DownloadPdf(pdf,root_url): path = "C:/Users/Downloads/cvx/" + pdf[9:] urls = root_url + pdf r = requests.get(urls) f = open(path, "wb") f.write(r.content) f.close() return urls url = "https://web.stanford.edu/class/ee364b/lectures.html" root_url = "https://web.stanford.edu/class/ee364b/" #print(GetList(GetPage(url))) pdfs = GetList(GetPage(url)) for pdf in pdfs: print("Download finished: "+DownloadPdf(pdf, root_url))
還有計劃把Standford的cs224n的lecture slides下載下來慢慢看,就在這個程式碼的基礎上改吧