pip install requestsOr download it directly from tu a nainštalovať manuálne.
Sťahovanie súborov
Python3# imported the requests library import requests image_url = 'https://www.python.org/static/community_logos/python-logo-master-v3-TM.webp' # URL of the image to be downloaded is defined as image_url r = requests.get(image_url) # create HTTP response object # send a HTTP request to the server and save # the HTTP response in a response object called r with open('python_logo.webp''wb') as f: # Saving received content as a png file in # binary format # write the contents of the response (r.content) # to a new file in binary mode. f.write(r.content)
This small piece of code written above will download the following image from the web. Now check your local directory(the folder where this script resides) and you will find this image: All we need is the URL of the image source. (You can get the URL of image source by right-clicking on the image and selecting the View Image option.) Stiahnite si veľké súbory
Obsah odpovede HTTP ( r.obsah ) nie je nič iné ako reťazec, ktorý ukladá údaje súboru. V prípade veľkých súborov teda nebude možné uložiť všetky údaje do jedného reťazca. Na prekonanie tohto problému robíme v našom programe niekoľko zmien:r = requests.get(URL stream = True)Setting prúd parameter do Pravda spôsobí sťahovanie iba hlavičiek odpovedí a spojenie zostane otvorené. Tým sa zabráni načítaniu obsahu naraz do pamäte pre veľké odozvy. Zakaždým sa načíta pevný blok r.iter_content is iterated. Here is an example: Python3
import requests file_url = 'http://codex.cs.yale.edu/avi/db-book/db4/slide-dir/ch1-2.pdf' r = requests.get(file_url stream = True) with open('python.pdf''wb') as pdf: for chunk in r.iter_content(chunk_size=1024): # writing one chunk at a time to pdf file if chunk: pdf.write(chunk)
Sťahovanie videí
V tomto príklade máme záujem stiahnuť si všetky dostupné video prednášky webovú stránku . Všetky archívy tejto prednášky sú dostupné tu . So we first scrape the webpage to extract all video links and then download the videos one by one. Python3
import requests from bs4 import BeautifulSoup ''' URL of the archive web-page which provides link to all video lectures. It would have been tiring to download each video manually. In this example we first crawl the webpage to extract all the links and then download videos. ''' # specify the URL of the archive here archive_url = 'https://public.websites.umich.edu/errors/404.html def get_video_links(): # create response object r = requests.get(archive_url) # create beautiful-soup object soup = BeautifulSoup(r.content'html5lib') # find all links on web-page links = soup.findAll('a') # filter the link sending with .mp4 video_links = [archive_url + link['href'] for link in links if link['href'].endswith('mp4')] return video_links def download_video_series(video_links): for link in video_links: '''iterate through all links in video_links and download them one by one''' # obtain filename by splitting url and getting # last string file_name = link.split('/')[-1] print( 'Downloading file:%s'%file_name) # create response object r = requests.get(link stream = True) # download started with open(file_name 'wb') as f: for chunk in r.iter_content(chunk_size = 1024*1024): if chunk: f.write(chunk) print( '%s downloaded!n'%file_name ) print ('All videos downloaded!') return if __name__ == '__main__': # getting all video links video_links = get_video_links() # download all videos download_video_series(video_links)
Advantages of using Requests library to download web files are: - Jeden môže ľahko stiahnuť webové adresáre rekurzívnym opakovaním cez webovú stránku!
- Toto je metóda nezávislá od prehliadača a oveľa rýchlejšia!
- Môžete jednoducho zoškrabať webovú stránku, aby ste získali všetky adresy URL súborov na webovej stránke, a teda stiahnuť všetky súbory jediným príkazom-
Implementácia škrabania webu v Pythone s BeautifulSoup