Http Post data from Python to net core app - python

I am trying to send a file from a Python script to my .net core webserver.
In Python I am doing this using the requests library, and my code looks like so.
filePath = "run-1.csv"
with open(filePath, "rb") as postFile:
file_dict = {filePath: postFile}
response = requests.post(server_path + "/batchUpload/create", files=file_dict, verify=validate_sql)
print (response.text)
This code executes fine, and I can see the request fine in my webserver code which looks like so:
[HttpPost]
[Microsoft.AspNetCore.Authorization.AllowAnonymous]
public string Create(IFormFile file) //Dictionary<string, IFormFile>
{
var ms = new MemoryStream();
file.CopyTo(ms);
var text = Encoding.ASCII.GetString(ms.ToArray());
Debug.Print(text);
return "s";
}
However, the file parameter always returns as null.
Also, I can see the file parameter fine when getting data posted from postMan
I suspect that this problem has to do with how .net core model binding works, but not sure...
Any suggestions here on how to get my file displaying on the server?

Solved my issue - the problem was that in Python I was assigning my file to my upload dictionary with the actual file name "./run1.csv" rather than a literal string "file"
Updating this fixed my issue.
file_dict = {"file": postFile}
This is what I believe #nalnpir mentioned above.
I figured this out by posting from postman and also from my python code to http://httpbin.org/post and comparing the respoinse

The example from the requests docs is mostly correct, except that the key has to match the parameter of the controller method signature.
url = 'https://www.url.com/api/post'
files = {'parameterName': open('filename.extension', 'rb')}
r = requests.post(url, files=files)
So in this case the controller action should be
[HttpPost]
public string Post(IFormFile parameterName)

Related

How do I use python requests to download a processed files?

I'm using Django 1.8.1 with Python 3.4 and i'm trying to use requests to download a processed file. The following code works perfect for a normal request.get command to download the exact file at the server location, or unprocessed file.
The file needs to get processed based on the passed data (shown below as "data"). This data will need to get passed into the Django backend, and based off the text pass variables to run an internal program from the server and output .gcode instead .stl filetype.
python file.
import requests, os, json
SERVER='http://localhost:8000'
authuser = 'admin#google.com'
authpass = 'passwords'
#data not implimented
##############################################
data = {FirstName:Steve,Lastname:Escovar}
############################################
category = requests.get(SERVER + '/media/uploads/9128342/141303729.stl', auth=(authuser, authpass))
#download to path file
path = "/home/bradman/Downloads/requestdata/newfile.stl"
if category.status_code == 200:
with open(path, 'wb') as f:
for chunk in category:
f.write(chunk)
I'm very confused about this, but I think the best course of action is to pass the data along with request.get, and somehow make some function to grab them inside my views.py for Django. Anyone have any ideas?
To use data in request you can do
get( ... , params=data)
(and you get data as parameters in url)
or
post( ... , data=data).
(and you send data in body - like HTML form)
BTW. some APIs need params= and data= in one request of GET or POST to send all needed information.
Read requests documentation

Upload image to facebook using the Python API

I have searched the web far and wide for a still working example of uploading a photo to facebook through the Python API (Python for Facebook). Questions like this have been asked on stackoverflow before but non of the answers I have found work anymore.
What I got working is:
import facebook as fb
cfg = {
"page_id" : "my_page_id",
"access_token" : "my_access_token"
}
api = get_api(cfg)
msg = "Hello world!"
status = api.put_wall_post(msg)
where I have defined the get_api(cfg) function as this
graph = fb.GraphAPI(cfg['access_token'], version='2.2')
# Get page token to post as the page. You can skip
# the following if you want to post as yourself.
resp = graph.get_object('me/accounts')
page_access_token = None
for page in resp['data']:
if page['id'] == cfg['page_id']:
page_access_token = page['access_token']
graph = fb.GraphAPI(page_access_token)
return graph
And this does indeed post a message to my page.
However, if I instead want to upload an image everything goes wrong.
# Upload a profile photo for a Page.
api.put_photo(image=open("path_to/my_image.jpg",'rb').read(), message='Here's my image')
I get the dreaded GraphAPIError: (#324) Requires upload file for which non of the solutions on stackoverflow works for me.
If I instead issue the following command
api.put_photo(image=open("path_to/my_image.jpg",'rb').read(), album_path=cfg['page_id'] + "/picture")
I get GraphAPIError: (#1) Could not fetch picture for which I haven't been able to find a solution either.
Could someone out there please point me in the right direction of provide me with a currently working example? It would be greatly appreciated, thanks !
A 324 Facebook error can result from a few things depending on how the photo upload call was made
a missing image
an image not recognised by Facebook
incorrect directory path reference
A raw cURL call looks like
curl -F 'source=#my_image.jpg' 'https://graph.facebook.com/me/photos?access_token=YOUR_TOKEN'
As long as the above calls works, you can be sure the photo agrees with Facebook servers.
An example of how a 324 error can occur
touch meow.jpg
curl -F 'source=#meow.jpg' 'https://graph.facebook.com/me/photos?access_token=YOUR_TOKEN'
This can also occur for corrupted image files as you have seen.
Using .read() will dump the actual data
Empty File
>>> image=open("meow.jpg",'rb').read()
>>> image
''
Image File
>>> image=open("how.png",'rb').read()
>>> image
'\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR\x00...
Both of these will not work with the call api.put_photo as you have seen and Klaus D. mentioned the call should be without read()
So this call
api.put_photo(image=open("path_to/my_image.jpg",'rb').read(), message='Here's my image')
actually becomes
api.put_photo('\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR\x00...', message='Here's my image')
Which is just a string, which isn't what is wanted.
One needs the image reference <open file 'how.png', mode 'rb' at 0x1085b2390>
I know this is old and doesn't answer the question with the specified API, however, I came upon this via a search and hopefully my solution will help travelers on a similar path.
Using requests and tempfile
A quick example of how I do it using the tempfile and requests modules.
Download an image and upload to Facebook
The script below should grab an image from a given url, save it to a file within a temporary directory and automatically cleanup after finished.
In addition, I can confirm this works running on a Flask service on Google Cloud Run. That comes with the container runtime contract so that we can store the file in-memory.
import tempfile
import requests
# setup stuff - certainly change this
filename = "your-desired-filename"
filepath = f"{directory}/{filename}"
image_url = "your-image-url"
act_id = "your account id"
access_token = "your access token"
# create the temporary directory
temp_dir = tempfile.TemporaryDirectory()
directory = temp_dir.name
# stream the image bytes
res = requests.get(image_url, stream=True)
# write them to your filename at your temporary directory
# assuming this works
# add logic for non 200 status codes
with open(filepath, "wb+") as f:
f.write(res.content)
# prep the payload for the facebook call
files = {
"filename": open(filepath, "rb"),
}
url = f"https://graph.facebook.com/v10.0/{act_id}/adimages?access_token={access_token}"
# send the POST request
res = requests.post(url, files=files)
res.raise_for_status()
if res.status_code == 200:
# get your image data back
image_upload_data = res.json()
temp_dir.cleanup()
if "images" in image_upload_data:
return image_upload_data["images"][filepath.split("/")[-1]]
return image_upload_data
temp_dir.cleanup() # paranoid: just in case an error isn't raised

Getting an empty file when served by django

I have the following code for managing file download through django.
def serve_file(request, id):
file = models.X.objects.get(id=id).file #FileField
file.open('rb')
wrapper = FileWrapper(file)
mt = mimetypes.guess_type(file.name)[0]
response = HttpResponse(wrapper, content_type=mt)
import unicodedata, os.path
filename = unicodedata.normalize('NFKD', os.path.basename(file.name)).encode("utf8",'ignore')
filename = filename.replace(' ', '-') #Avoid browser to ignore any char after the space
response['Content-Length'] = file.size
response['Content-Disposition'] = 'attachment; filename={0}'.format(filename)
#print response
return response
Unfortunately, my browser get an empty file when downloading.
The printed response seems correct:
Content-Length: 3906
Content-Type: text/plain
Content-Disposition: attachment; filename=toto.txt
blah blah ....
I have similar code running ok. I don't see what can be the problem. Any idea?
PS: I have tested the solution proposed here and get the same behavior
Update:
Replacing wrapper = FileWrapper(file) by wrapper = file.read() seems to fix the problem
Update: If I comment the print response, I get similar issue:. the file is empty. Only difference: FF detects a 20bytes size. (the file is bigger than this)
File object is an interable, and a generator. It can be read only once before being exausted. Then you have to make a new one, of use a method to start at the begining of the object again (e.g: seek()).
read() returns a string, which can be read multiple times without any problem, this is why it solves your issue.
So just make sure that if you use a file like object, you don't read it twice in a row. E.G: don't print it, then returns it.
From django documentation:
FieldFile.open(mode='rb') Behaves like the standard Python open()
method and opens the file associated with this instance in the mode
specified by mode.
If it works like pythons open then it should return a file-object, and should be used like this:
f = file.open('rb')
wrapper = FileWrapper(f)

The JSON syntax vs html/xml tags

The JSON syntax definition say that
html/xml tags (like the <script>...</script> part) are not part of
valid json, see the description at http://json.org.
A number of browsers and tools ignore these things silently, but python does
not.
I'd like to insert the javascript code (google analytics) to get info about the users using this service (place, browsers, OS ...).
What do you suggest to do?
I should solve the problem on [browser output][^1] or [python script][^2]?
thanks,
Antonio
[^1]: Browser output
<script>...</script>
[{"key": "value"}]
[^2]: python script
#!/usr/bin/env python
import urllib2, urllib, json
url="http://.........."
params = {}
url = url + '?' + urllib.urlencode(params, doseq=True)
req = urllib2.Request(url)
headers = {'Accept':'application/json;text/json'}
for key, val in headers.items():
req.add_header(key, val)
data = urllib2.urlopen(req)
print json.load(data)
These sound like two different kinds of services--one is a user-oriented web view of some data, with visualizations, formatting, etc., and one is a machine-oriented data service. I would keep these separate, and maybe build the user view as an extension to the data service.

upload binary data or file from memory using python http post

I have seen the receipes for uploading files via multipartform-data and pycurl. Both methods seem to require a file on disk. Can these recipes be modified to supply binary data from memory instead of from disk ? I guess I could just use a xmlrpc server instead.I wanted to get around having to encode and decode the binary data and send it raw... Do pycurl and mutlipartform-data work with raw data ?
This (small) library will take a file descriptor, and will do the HTTP POST operation: https://github.com/seisen/urllib2_file/
You can pass it a StringIO object (containing your in-memory data) as the file descriptor.
Find something that cas work with a file handle. Then simply pass a StringIO object instead of a real file descriptor.
I met similar issue today, after tried both and pycurl and multipart/form-data, I decide to read python httplib/urllib2 source code to find out, I did get one comparably good solution:
set Content-Length header(of the file) before doing post
pass a opened file when doing post
Here is the code:
import urllib2, os
image_path = "png\\01.png"
url = 'http://xx.oo.com/webserviceapi/postfile/'
length = os.path.getsize(image_path)
png_data = open(image_path, "rb")
request = urllib2.Request(url, data=png_data)
request.add_header('Cache-Control', 'no-cache')
request.add_header('Content-Length', '%d' % length)
request.add_header('Content-Type', 'image/png')
res = urllib2.urlopen(request).read().strip()
return res
see my blog post: http://www.2maomao.com/blog/python-http-post-a-binary-file-using-urllib2/
Following python code works reliable on 2.6.x. The input data is of type str.
Note that the server that receives the data has to loop to read all the data as the large
data sizes will be chunked. Also attached java code snippet to read the chunked data.
def post(self, url, data):
self.curl = pycurl.Curl()
self.response_headers = StringIO.StringIO()
self.response_body = io.BytesIO()
self.curl.setopt(pycurl.WRITEFUNCTION, self.response_body.write)
self.curl.setopt(pycurl.HEADERFUNCTION, self.response_headers.write)
self.curl.setopt(pycurl.FOLLOWLOCATION, 1)
self.curl.setopt(pycurl.MAXREDIRS, 5)
self.curl.setopt(pycurl.TIMEOUT, 60)
self.curl.setopt(pycurl.ENCODING,"deflate, gzip")
self.curl.setopt(pycurl.URL, url)
self.curl.setopt(pycurl.VERBOSE, 1)
self.curl.setopt(pycurl.POST,1)
self.curl.setopt(pycurl.POSTFIELDS,data)
self.curl.setopt(pycurl.HTTPHEADER, [ "Content-Type: octate-stream" ])
self.curl.setopt(pycurl.POSTFIELDSIZE, len(data))
self.curl.perform()
return url, self.curl.getinfo(pycurl.RESPONSE_CODE),self.response_headers.getvalue(), self.response_body.getvalue()
Java code for the servlet engine:
int postSize = Integer.parseInt(req.getHeader("Content-Length"));
results = new byte[postSize];
int read = 0;
while(read < postSize) {
int n = req.getInputStream().read(results);
if (n < 0) break;
read += n;
}
found a solution that works with the cherrypy file upload example: urllib2-binary-upload.py
import io # Part of core Python
import requests # Install via: 'pip install requests'
# Get the data in bytes. I got it via:
# with open("smile.gif", "rb") as fp: data = fp.read()
data = b"GIF89a\x12\x00\x12\x00\x80\x01\x00\x00\x00\x00\xff\x00\x00!\xf9\x04\x01\n\x00\x01\x00,\x00\x00\x00\x00\x12\x00\x12\x00\x00\x024\x84\x8f\x10\xcba\x8b\xd8ko6\xa8\xa0\xb3Wo\xde9X\x18*\x15x\x99\xd9'\xad\x1b\xe5r(9\xd2\x9d\xe9\xdd\xde\xea\xe6<,\xa3\xd8r\xb5[\xaf\x05\x1b~\x8e\x81\x02\x00;"
# Hookbin is similar to requestbin - just a neat little service
# which helps you to understand which queries are sent
url = 'https://hookb.in/je2rEl733Yt9dlMMdodB'
in_memory_file = io.BytesIO(data)
response = requests.post(url, files=(("smile.gif", in_memory_file),))

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