I have a local python file that decodes binary files. This python file first reads from the file, opens it as binary and then saves it in a buffer and interprets it. Reading it is simply:
with open(filepath, 'rb') as f:
buff = f.read()
read_all(buff)
This works fine locally. Now I'd like to setup a Azure Python job where I can send the file, approx. 100kb, over a HTTP POST and then read the interpreted meta data which my original python script does well.
I've first removed the read function so that I'll now work with the buffer only.
In my Azure Python Job I have the following, triggered by a HttpRequest
my_data = reader.read_file(req.get_body())
To test my sending I've tried the following in python
import requests
url = 'http://localhost:7071/api/HttpTrigger'
files = {'file': open('test', 'rb')}
with open('test', 'rb') as f:
buff = f.read()
r = requests.post(url, files=files) #Try using files
r = requests.post(url, data=buff) #Try using data
I've also tried in Postman adding the file to the body as a binary and setting the headers to application/octet-stream
All this doesn't send the binary file the same way as the original f.read() did. So I'm getting a wrong interpretation of the binary file.
What is file.read doing differently to how I'm sending it over as a HTTP Body message?
Printing out the first line from the local python read file gives.
b'\n\n\xfe\xfe\x00\x00\x00\x00\\\x18,A\x18\x00\x00\x00(\x00\x00\x00\x1f\x00\x00\
Whereas printing it out at the req.get_body() shows me
b'\n\n\xef\xbf\xbd\xef\xbf\xbd\x00\x00\x00\x00\\\x18,A\x18\x00\x00\x00(\x00\x00\x00\x1f\x00\
So something is clearly wrong. Any help why this could be different?
Thanks
EDIT:
I've implemented a similar function in Flask and it works well.
The code in flask is simply grabbing the file from a POST. No encoding/decoding.
if request.method == 'POST':
f = request.files['file']
#f.save(secure_filename(f.filename))
my_data = reader.read_file(f.read())
Why is the Azure Function different?
You can try UTF-16 to decode and do the further action in your code.
Here is the code for that:
with open(path_to_file,'rb') as f:
contents = f.read()
contents = contents.rstrip("\n").decode("utf-16")
Basically after doing re.get_body, perform the below operation:
contents = contents.rstrip("\n").decode("utf-16")
See if it gives you the same output as your receive in local python file.
Hope it helps.
Related
I have this code for server
#app.route('/get', methods=['GET'])
def get():
return send_file("token.jpg", attachment_filename=("token.jpg"), mimetype='image/jpg')
and this code for getting response
r = requests.get(url + '/get')
And i need to save file from response to hard drive. But i cant use r.files. What i need to do in these situation?
Assuming the get request is valid. You can use use Python's built in function open, to open a file in binary mode and write the returned content to disk. Example below.
file_content = requests.get('http://yoururl/get')
save_file = open("sample_image.png", "wb")
save_file.write(file_content.content)
save_file.close()
As you can see, to write the image to disk, we use open, and write the returned content to 'sample_image.png'. Since your server-side code seems to be returning only one file, the example above should work for you.
You can set the stream parameter and extract the filename from the HTTP headers. Then the raw data from the undecoded body can be read and saved chunk by chunk.
import os
import re
import requests
resp = requests.get('http://127.0.0.1:5000/get', stream=True)
name = re.findall('filename=(.+)', resp.headers['Content-Disposition'])[0]
dest = os.path.join(os.path.expanduser('~'), name)
with open(dest, 'wb') as fp:
while True:
chunk = resp.raw.read(1024)
if not chunk: break
fp.write(chunk)
I have a jpg image that is stored at a url that I need to access and read the binary/byte data from.
I can get the file in Python by using:
import urllib3
http = urllib3.PoolManager()
url = 'link to jpg'
contents = http.request('GET' url)
Purely reading the data from this request with contents.data doesn't provide the correct binary but if I download the file and read it locally, I get the correct binary. But I cannot continue with reading the file contents as such:
with open(contents, "rb") as image:
f = image.read()
Using the bytes from the request doesn't work either:
with open(contents.data, "rb") as image:
f = image.read()
How can I treat the jpg from the url as if it were local so that I can read the binary correctly?
The result obtained in f when file is read locally and the result of contents.data is exactly the same.
import urllib3
http = urllib3.PoolManager()
url = 'https://tinyjpg.com/images/social/website.jpg'
contents = http.request('GET', url)
with open('website.jpg', "rb") as image:
f = image.read()
print(f==contents.data)
You can download the image from the link in the code and then run this code, you will receive output True which implies the data read from local image file is same as data read from website.
I am trying to setup a script where I upload a file (now using the python requests library) to a Flask environment that runs inside of a Docker (-compose) container. The python script is ran in the hypervisor, and I force it to use the same version of python (3.6) as well. I am able to get responses from the server, but the file I upload is 12Kb, and the file the Flask container receives is 2Kb, and I have no clue what is going wrong.
It seems like when I use WireShark to capture the tcp stream, I receive a 2Kb file as well, so my guess the requests library applies some compression, but I can not seem to find any documentation about this happening.
I have tried to replace the file tuple in the sending code with solely the file handle, but this seemed to have no effect. Sending files of a different size results in a different filesize in Flask / Docker.
Sending a string instead of the filehandler ("1234567890") results in the filesize being as big as the string length (10 bytes).
Replacing the file opening method from rb to r results in a UnicodeDecodeError: 'ascii' codec can't decode byte 0xdf in position 14: ordinal not in range(128) raise inside requests -> encodings.
Hypervisor: send.py
import requests
with open('file.docx', 'rb') as f:
url = 'http://localhost:8081/file'
r = requests.post(url, files={'file': ('file', f, 'multipart/form-data')})
print(r.text)
Flask: file.py
#app.route('/file', methods=['POST'])
def parse_from_post():
file = request.files['file']
fn = secure_filename("file.docx") # did this manually instead of getting it from the request for testing reasons
folder = "/app/files/"
fl = os.path.join(folder, fn)
# Removes old file
if os.path.exists(fl):
os.remove(fl)
file.save(fl)
return ""
The problem lies with the filesize, which python requests does not take care of directly. I used the MultipartEncoder from the requests_toolbelt package, to encapsulate the file instead of directly plugging in the file in the requests post call.
Hypervisor: send.py
import requests
from requests_toolbelt import MultipartEncoder
with open('file.docx', 'rb') as f:
url = 'http://localhost:8081/file'
m = MultipartEncoder(fields={
"file": ("file.docx", f)
})
r = requests.post(url, data=m, headers={'Content-Type': m.content_type})
print(r.text)
I actually found this result from another post on SO, see the first comment on the question linking to https://toolbelt.readthedocs.io/....
I am trying to download file from GitHub(raw file) and then run this file as .sql file.
import snowflake.connector
from codecs import open
import logging
import requests
from os import getcwd
import os
import sys
#logging
logging.basicConfig(
filename='C:/Users/abc/Documents/Test.log',
level=logging.INFO
)
url = "https://github.com/raw/abc/master/file_name?token=Anvn3lJXDks5ciVaPwA%3D%3D"
directory = getcwd()
filename = os.path.join(getcwd(),'VIEWS.SQL')
r = requests.get(url)
filename.decode("utf-8")
f = open(filename,'w')
f.write(str(r.content))
with open(filename,'r') as theFile, open(filename,'w') as outFile:
data = theFile.read().split('\n')
data = theFile.read().replace('\n','')
data = theFile.read().replace("b'","")
data = theFile.read()
outFile.write(data)
However I get this error
syntax error line 1 at position 0 unexpected 'b'
My converted sql file has b at the beginning and bunch of newline \n characters in the file. Also the entire output file is in single quotes 'text'. Can anyone help me get rid of these? Looks like replace isn't working.
OS: Windows
Python Version: 3.7.0
You introduced a b'.. prefix by converting the response.content bytes value to a string with str():
>>> import requests
>>> r = requests.get("https://github.com/raw/abc/master/file_name?token=Anvn3lJXDks5ciVaPwA%3D%3D")
>>> r.content
b'Not Found'
>>> str(r.content)
"b'Not Found'"
Of course, the specific dummy URL you gave in your question produces a 404 Not Found response, hence the Not Found content of the response body:
>>> r.status_code
404
so the contents in this demonstration are not actually all that useful. However, even for your real URL you probably want to test for a 200 status code before moving to write the data to a file!
What is going wrong in the above is that str(bytesvalue) converts a bytes object to its representation. You'd normally want to decode a bytes value with a text codec, using the bytes.decode() method. But because you are writing the data to a file here, you should instead just open the file in binary mode and write the bytes object without decoding:
r = requests.get(url)
if r.status_code == 200:
with open(filename, 'wb') as f:
f.write(r.content)
The 'wb' mode opens the file for writing in binary mode. Writing binary content to a binary file is the most efficient; decoding it first then writing to a text file requires that it is encoded again. Better to avoid doing double work.
As a side note: there is no need to join a local filename with getcwd(); relative paths always end up in the current working directory, and otherwise it's better to use os.path.abspath(filename).
You could also trust that GitHub sets the correct character set in the Content-Type headers and have response decode the value to str for you in the form of the response.text attribute:
r = requests.get(url)
if r.status_code == 200:
with open(filename, 'w') as f:
f.write(r.text)
but again, that's really doing extra work for nothing, first decoding the binary content from the request, then encoding again when writing to a text file.
Finally, for larger file responses it is better to stream the data and copy it directly to a file. The shutil.copyfileobj() function can take a raw response fileobject directly, provided you enable transparent transport decompression:
import shutil
r = requests.get(url, stream=True)
if r.status_code == 200:
with open(filename, 'wb') as f:
# enable transparent transport decompression handling
r.raw.decode_content = True
shutil.copyfileobj(r.raw, f)
Depending on your version of Python/OS it could be as simple as changing the file to read/write in binary (and if they're still there then altering where you have the replaces):
with open(filename,'rb') as theFile, open(filename,'wb') as outFile:
outfile.write(str(r.content))
data = theFile.read().split('\n')
data = data.replace('\n','')
data = data.replace("b'","")
outFile.write(data)
It would help to have a copy of the file and the line the error is occurring on.
I am trying to upload a file using python requests module and i am not sure whether we can use both data and files in the post call.
fileobj= open(filename,'rb')
upload_data = {
'data':payload,
'file':fileobj
}
resp = s.post(upload_url,data=upload_data,headers=upload_headers)
and this is not working. So can anyone help me with this ?
I think you should be using the data and files keyword parameters in the post request to send the data and file respectively.
with open(filename,'rb') as fileobj:
files = {'file': fileobj}
resp = s.post(upload_url,data=payload,files=files,headers=upload_headers)
I've also use a context manager just because it closes the file for me and takes care of exceptions that happen either during file opening or during something that happens with the requests post.