I am trying to upload a file through python requests using the PUT method. But on the server side, the file is never received.
The code that I am using is:
files = {'test' : open(r"C:\Users\test.jar", 'rb')}
response = session.put(api_base + url.get('url').format(foo, bar),
headers=headers, data=data, files=files)
Does PUT ignore file uploads? Is it only valid for posts?
What am I doing wrong?
It seems that Python's request module does not work for file uploads if you use the PUT method as you did. The documentation only shows one way to use POST requests. I'm not sure if this is a bug or not working intentionally.
Others also have problems using PUT requests for file transfer, see e.g:
Cannot PUT file to Django REST API by python requests
Python requests PUT method creates a zero byte file
OP moved to PycURL, which seems to work and also seems to be a good alternative.
I'm trying to write a (simple) piece of code to download files off the internet. The problem is, some of these files are on websites that block the default python User-Agent headers. For example:
import urllib.request as html
html.urlretrieve('http://stackoverflow.com', 'index.html')
returns
urllib.error.HTTPError: HTTP Error 403: Forbidden`
Normally, I would set the headers in the request, such as:
import urllib.request as html
request = html.Request('http://stackoverflow.com', headers={"User-Agent":"Firefox"})
response = html.urlopen(request)
however, as urlretrieve doesn't work with requests for some reason, this isn't an option.
Are there any simple-ish solutions to this (that don't include importing a library such as requests)? I've noticed that urlretrieve is part of the legacy interface posted over from Python 2, is there anything I should be using instead?
I tried creating a custom FancyURLopener class to handle retrieving files, but that caused more problems than it solved, such as creating empty files for links that 404.
You can subclass URLopener and set the version class variable to a different user-agent then continue using urlretrieve.
Or you can simply use your second method and save the response to a file only after checking that code == 200.
If I were trying to google something, how would I send the data I want to search to be searched? I know you can add it to the url, but I do not want to do this.
Using the requests library. You would use the .post method in the same way as the .get method. Passing in the data as a dictionary to the data parameter of the function.
The quickstart docs describe it here http://requests.readthedocs.org/en/latest/user/quickstart/#more-complicated-post-requests
If using urllib or urllib2 the data parameter of the urlopen function will POST the data to the page rather than GET it.
see the docs here http://docs.python.org/library/urllib.html#urllib.urlopen
I'm using MultipartPostHandler in file sending. My code is following:
params = {'file':open(file_name, 'rb')}
headers = {'cookie':session_id}
urllib2.install_opener(urllib2.build_opener(MultipartPostHandler.MultipartPostHandler))
response = urllib2.urlopen(urllib2.Request("www.example.com/upload", params, headers))
How could I do the same (send file to the server) without using MultipartPostHandler? It would be good to use only buid-in python modules and urllib2. Is it possible.
MultipartPostHandler needs to install it using easy_install, pip or
from source. I want like to write the python script that would not
require new instalations.
Just add it to your original script - it is just one file. Copy paste the code for the module.
Unfortunately, there is no direct method available to post a multiple part file using urllib2. But there are ways to accomplish that by writing a custom form object using mimetype and mimetools module. You could follow this recipe and adopt your form to do a mutipart upload using urllib2.
(In Python3, urllib.request data can take a pointer to file object and that does read the whole file into memory)
I wrote a web crawler in Python 2.6 using the Bing API that searches for certain documents and then downloads them for classification later. I've been using string methods and urllib.urlretrieve() to download results whose URL ends in .pdf, .ps etc., but I run into trouble when the document is 'hidden' behind a URL like:
http://www.oecd.org/officialdocuments/displaydocument/?cote=STD/CSTAT/WPNA(2008)25&docLanguage=En
So, two questions. Is there a way in general to tell if a URL has a pdf/doc etc. file that it's linking to if it's not doing so explicitly (e.g. www.domain.com/file.pdf)? Is there a way to get Python to snag that file?
Edit:
Thanks for replies, several of which suggest downloading the file to see if it's of the correct type. Only problem is... I don't know how to do that (see question #2, above). urlretrieve(<above url>) gives only an html file with an href containing that same url.
There's no way to tell from the URL what it's going to give you. Even if it ends in .pdf it could still give you HTML or anything it likes.
You could do a HEAD request and look at the content-type, which, if the server isn't lying to you, will tell you if it's a PDF.
Alternatively you can download it and then work out whether what you got is a PDF.
In this case, what you refer to as "a document that's not explicitly referenced in a URL" seems to be what is known as a "redirect". Basically, the server tells you that you have to get the document at another URL. Normally, python's urllib will automatically follow these redirects, so that you end up with the right file. (and - as others have already mentioned - you can check the response's mime-type header to see if it's a pdf).
However, the server in question is doing something strange here. You request the url, and it redirects you to another url. You request the other url, and it redirects you again... to the same url! And again... And again... At some point, urllib decides that this is enough already, and will stop following the redirect, to avoid getting caught in an endless loop.
So how come you are able to get the pdf when you use your browser? Because apparently, the server will only serve the pdf if you have cookies enabled. (why? you have to ask the people responsible for the server...) If you don't have the cookie, it will just keep redirecting you forever.
(check the urllib2 and cookielib modules to get support for cookies, this tutorial might help)
At least, that is what I think is causing the problem. I haven't actually tried doing it with cookies yet. It could also be that the server is does not "want" to serve the pdf, because it detects you are not using a "normal" browser (in which case you would probably need to fiddle with the User-Agent header), but it would be a strange way of doing that. So my guess is that it is somewhere using a "session cookie", and in the case you haven't got one yet, keeps on trying to redirect.
As has been said there is no way to tell content type from URL. But if you don't mind getting the headers for every URL you can do this:
obj = urllib.urlopen(URL)
headers = obj.info()
if headers['Content-Type'].find('pdf') != -1:
# we have pdf file, download whole
...
This way you won't have to download each URL just it's headers. It's still not exactly saving network traffic, but you won't get better than that.
Also you should use mime-types instead of my crude find('pdf').
No. It is impossible to tell what kind of resource is referenced by a URL just by looking at it. It is totally up to the server to decide what he gives you when you request a certain URL.
Check the mimetype with the urllib.info() function. This might not be 100% accurate, it really depends on what the site returns as a Content-Type header. If it's well behaved it'll return the proper mime type.
A PDF should return application/pdf, but that may not be the case.
Otherwise you might just have to download it and try it.
You can't see it from the url directly. You could try to only download the header of the HTTP response and look for the Content-Type header. However, you have to trust the server on this - it could respond with a wrong Content-Type header not matching the data provided in the body.
Detect the file type in Python 3.x and webapp with url to the file which couldn't have an extension or a fake extension. You should install python-magic, using
pip3 install python-magic
For Mac OS X, you should also install libmagic using
brew install libmagic
Code snippet
import urllib
import magic
from urllib.request import urlopen
url = "http://...url to the file ..."
request = urllib.request.Request(url)
response = urlopen(request)
mime_type = magic.from_buffer(response.read())
print(mime_type)