I have been having problems with a script I am developing whereby I am receiving no output and the memory usage of the script is getting larger and larger over time. I have figured out the problem lies with some of the URLs I am checking with the Requests library. I am expecting to download a webpage however I download a large file instead. All this data is then stored in memory causing my issues.
What I want to know is; is there any way with the requests library to check what is being downloaded? With wget I can see: Length: 710330974 (677M) [application/zip].
Is this information available in the headers with requests? If so is there a way of terminating the download upon figuring out it is not a HTML webpage?
Thanks in advance.
Yes, the headers can tell you a lot about the page, most pages will include a Content-Length header.
By default, however, the request is downloaded in its entirety before the .get() or .post(), etc. call returns. Set the stream=True keyword to defer loading the response:
response = requests.get(url, stream=True)
Now you can inspect the headers and just discard the request if you don't like what you find:
length = int(response.headers.get('Content-Length', 0))
if length > 1048576:
print 'Response larger than 1MB, discarding
Subsequently accessing the .content or .text attributes, or the .json() method will trigger a full download of the response.
Related
I have a database of thousands of files online, and I want to check what their status is (e.g. if the file exists, if it sends us to a 404, etc.) and update this in my database.
I've used urllib.request to download files to a python script. However, obviously downloading terabytes of files is going to take a long time. Parallelizing the process would help, but ultimately I just don't want to download all the data, just check the status. Is there an ideal way to check (using urllib or another package) the HTTP response code of a certain URL?
Additionally, if I can get the file size from the server (which would be in the HTTP response), then I can also update this in my database.
If your web server is standards-based, you can use a HEAD request instead of a GET. It returns the same status without actually fetching the page.
The requests module can check the status response of a request.
Just do:
import requests
url = 'https://www.google.com' # Change to your link
response = requests.get(url)
print(response.status_code)
this code shows me 200, so the request has been successful
I am trying to download torrent file from this code :
url = "https://itorrents.org/torrent/0BB4C10F777A15409A351E58F6BF37E8FFF53CDB.torrent"
r = requests.get(url, allow_redirects=True)
open('test123.torrent', 'wb').write(r.content)
It downloads a torrent file , but when i load it to bittorrent error occurs.
It says Unable to Load , Torrent Is Not Valid Bencoding
Can anybody please help me to resolve this problem ? Thanks in advance
This page use cloudflare to prevent scraping the page,I am sorry to say that bypassing cloudflare is very hard if you only use requests, the measures cloudflare takes will update soon.This page will check your browser whether it support Javascript.If not, they won't give you the bytes of the file.That's why you couldn't use them.(You could use r.text to see the response content, it is a html page.Not a file.)
Under this circumstance, I think you should consider about using selenium.
Bypassing Cloudflare can be a pain, so I suggest using a library that handles it. Please don't forget that your code may break in the future because Cloudflare changes their techniques periodically. Well, if you use the library, you will just need to update the library (at least you should hope for that).
I used a similar library only in NodeJS, but I see python also has something like that - cloudscraper
Example:
import cloudscraper
scraper = cloudscraper.create_scraper() # returns a CloudScraper instance
# Or: scraper = cloudscraper.CloudScraper() # CloudScraper inherits from requests.Session
print scraper.get("http://somesite.com").text # => "<!DOCTYPE html><html><head>..."
Depending on your usage you may need to consider using proxies - CloudFlare can still block you if you send too many requests.
Also, if you are working with video torrents, you may be interested in Torrent Stream Server. It a server that downloads and streams video at the same time, so you can watch the video without fully downloading it.
We can do by adding cookies in headers .
But after some time cookie expires.
Therefore only solution is to download from opening browser
I would like to try send requests.get to this website:
requests.get('https://rent.591.com.tw')
and I always get
<Response [404]>
I knew this is a common problem and tried different way but still failed.
but all of other website is ok.
any suggestion?
Webservers are black boxes. They are permitted to return any valid HTTP response, based on your request, the time of day, the phase of the moon, or any other criteria they pick. If another HTTP client gets a different response, consistently, try to figure out what the differences are in the request that Python sends and the request the other client sends.
That means you need to:
Record all aspects of the working request
Record all aspects of the failing request
Try out what changes you can make to make the failing request more like the working request, and minimise those changes.
I usually point my requests to a http://httpbin.org endpoint, have it record the request, and then experiment.
For requests, there are several headers that are set automatically, and many of these you would not normally expect to have to change:
Host; this must be set to the hostname you are contacting, so that it can properly multi-host different sites. requests sets this one.
Content-Length and Content-Type, for POST requests, are usually set from the arguments you pass to requests. If these don't match, alter the arguments you pass in to requests (but watch out with multipart/* requests, which use a generated boundary recorded in the Content-Type header; leave generating that to requests).
Connection: leave this to the client to manage
Cookies: these are often set on an initial GET request, or after first logging into the site. Make sure you capture cookies with a requests.Session() object and that you are logged in (supplied credentials the same way the browser did).
Everything else is fair game but if requests has set a default value, then more often than not those defaults are not the issue. That said, I usually start with the User-Agent header and work my way up from there.
In this case, the site is filtering on the user agent, it looks like they are blacklisting Python, setting it to almost any other value already works:
>>> requests.get('https://rent.591.com.tw', headers={'User-Agent': 'Custom'})
<Response [200]>
Next, you need to take into account that requests is not a browser. requests is only a HTTP client, a browser does much, much more. A browser parses HTML for additional resources such as images, fonts, styling and scripts, loads those additional resources too, and executes scripts. Scripts can then alter what the browser displays and load additional resources. If your requests results don't match what you see in the browser, but the initial request the browser makes matches, then you'll need to figure out what other resources the browser has loaded and make additional requests with requests as needed. If all else fails, use a project like requests-html, which lets you run a URL through an actual, headless Chromium browser.
The site you are trying to contact makes an additional AJAX request to https://rent.591.com.tw/home/search/rsList?is_new_list=1&type=1&kind=0&searchtype=1®ion=1, take that into account if you are trying to scrape data from this site.
Next, well-built sites will use security best-practices such as CSRF tokens, which require you to make requests in the right order (e.g. a GET request to retrieve a form before a POST to the handler) and handle cookies or otherwise extract the extra information a server expects to be passed from one request to another.
Last but not least, if a site is blocking scripts from making requests, they probably are either trying to enforce terms of service that prohibit scraping, or because they have an API they rather have you use. Check for either, and take into consideration that you might be blocked more effectively if you continue to scrape the site anyway.
One thing to note: I was using requests.get() to do some webscraping off of links I was reading from a file. What I didn't realise was that the links had a newline character (\n) when I read each line from the file.
If you're getting multiple links from a file instead of a Python data type like a string, make sure to strip any \r or \n characters before you call requests.get("your link"). In my case, I used
with open("filepath", 'w') as file:
links = file.read().splitlines()
for link in links:
response = requests.get(link)
In my case this was due to fact that the website address was recently changed, and I was provided the old website address. At least this changed the status code from 404 to 500, which, I think, is progress :)
When I use the python requests module, calling requests.get(url), I have found that the response from the url is being truncated.
import requests
url = 'https://gtfsrt.api.translink.com.au/Feed/SEQ'
response = requests.get(url)
print response.text
The response I get from the URL is being truncated. Is there a way to get requests to retrieve the full set of data and not truncate it?
Note: The given URL is a public transport feed which puts out a huge quantity data during the peak of day.
I ran into the same issue. The problem is not your Python code. It might be PyCharm or Utility you are using - The console has a buffer limit. You may have to increase that to see your full response.
Refer to this article for more help:
Increase output buffer when running or debugging in PyCharm
Add "gzip":true to your request options.
That fixed the issue for me.
I have a service to which I need to upload the content and the server starts sending the response after it gets certain amount of data, while my request body is still uploading.
headers = {'Content-Type': 'application/octet-stream', 'Expect': '100-continue', 'Connection' :'keep-alive'}
url = "https://MY_API_URL/WEBSERVICE"
response = requests.put(url, headers=headers,stream=True, data=data_gen(fh))
lines = response.iter_lines()
for line in lines:
print line
data_gen is my generator function which takes a file handle of a very large file that yields 4KB per iteration.
My problem is that I dont get the "response" until the whole file uploads. Any ideas on how I can overcome this.
You cannot accomplish this with requests today. Requests (and the underlying libraries, including httplib/http.client [depending on your version of Python]) all send all of the data before they start reading the response.
One library that may be able to handle this (in fact, I'm fairly certain this should be doable with it) is treq. It uses Twisted which should give you ways to determine when data is received so all you should need to do is register a callback to start accessing that data.