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How to access authentication by Strava API using Python?

I am starting a small python script (not an application) that can upload my *.fit activity files on Strava whenever they are created in a desired folder.
The main steps I plan to do are:
1. monitor *.fit file system modifications
2. access authentication to Strava to enable my program to upload files
(This tool will be personal use only, thus I expect no need to authenticate every time uploading)
3. upload the file to my Strava account
4. automatically doing this fixed routine with the help of Windows Task Scheduler
(For example, there will be 4-5 new riding activities generated in my computer folder, I expect this tool can automatically upload all of them once a week so that I do not need to manually complete the task.)
For step2, I really have no ideas how to implement even though reading through Strava Authentication Documentation and several source codes other peoples have developed (e.g. toravir's "rk2s (RunKeeper 2 Strava)" project on GitHub). I grabbed that some of the python modules like stravalib, swagger_client, request, json, etc. as well as concepts like OAuth2 may be related to step2 but I still can not put everything together...
Can any experienced give me some advice for the implementations of step2? or any related readings will be perfect!
Advice for other parts of this project will also be very welcomed and appreciated.
I thank you very much in advance:)

This is a code example on how you can access the Strava API, check out this gist or use the code below:
import time
import pickle
from fastapi import FastAPI
from fastapi.responses import RedirectResponse
from stravalib.client import Client
CLIENT_ID = 'GET FROM STRAVA API SITE'
CLIENT_SECRET = 'GET FROM STRAVA API SITE'
REDIRECT_URL = 'http://localhost:8000/authorized'
app = FastAPI()
client = Client()
def save_object(obj, filename):
with open(filename, 'wb') as output: # Overwrites any existing file.
pickle.dump(obj, output, pickle.HIGHEST_PROTOCOL)
def load_object(filename):
with open(filename, 'rb') as input:
loaded_object = pickle.load(input)
return loaded_object
def check_token():
if time.time() > client.token_expires_at:
refresh_response = client.refresh_access_token(client_id=CLIENT_ID, client_secret=CLIENT_SECRET, refresh_token=client.refresh_token)
access_token = refresh_response['access_token']
refresh_token = refresh_response['refresh_token']
expires_at = refresh_response['expires_at']
client.access_token = access_token
client.refresh_token = refresh_token
client.token_expires_at = expires_at
#app.get("/")
def read_root():
authorize_url = client.authorization_url(client_id=CLIENT_ID, redirect_uri=REDIRECT_URL)
return RedirectResponse(authorize_url)
#app.get("/authorized/")
def get_code(state=None, code=None, scope=None):
token_response = client.exchange_code_for_token(client_id=CLIENT_ID, client_secret=CLIENT_SECRET, code=code)
access_token = token_response['access_token']
refresh_token = token_response['refresh_token']
expires_at = token_response['expires_at']
client.access_token = access_token
client.refresh_token = refresh_token
client.token_expires_at = expires_at
save_object(client, 'client.pkl')
return {"state": state, "code": code, "scope": scope}
try:
client = load_object('client.pkl')
check_token()
athlete = client.get_athlete()
print("For {id}, I now have an access token {token}".format(id=athlete.id, token=client.access_token))
# To upload an activity
# client.upload_activity(activity_file, data_type, name=None, description=None, activity_type=None, private=None, external_id=None)
except FileNotFoundError:
print("No access token stored yet, visit http://localhost:8000/ to get it")
print("After visiting that url, a pickle file is stored, run this file again to upload your activity")
Download that file, install the requirements, and run it (assuming the filename is main):
pip install stravalib
pip install fastapi
pip install uvicorn
uvicorn main:app --reload

I believe you need to authenticate using OAuth in order to upload your activity, which pretty much requires you to have a web server setup that Strava can post back to after you "Authorize". I just set the authentication piece up using Rails & Heroku.
This link has a pretty good flowchart of what needs to happen.
https://developers.strava.com/docs/authentication/

Actually it looks like if you go to API Settings you can get your access token and refresh token there. I would also check out the Python Strava Library but it looks like you could do something like:
from stravalib.client import Client
access_token = 'your_access_token_from_your_api_application_settings_page'
refresh_token = 'your_refresh_token_from_your_api_application_settings_page'
client = Client()
athlete = client.get_athlete()
You may need to dig in a little more to that library to figure out the upload piece.

Flask stream/multipart file from S3

I'm using Flask in AWS Api Gateway/Lambda environment (Thanks to Zappa), but there is a limit in response size, so Flask's send_file is not enough in this context.
Is there a way I can stream/multipart(not sure if these are the correct terms) a file-like object as response in Flask? I can't send request bodies with more than 5mb(6mb?) in the AWS Serverless environment.
Current code (simple S3 proxy that deletes the object once downloaded):
#app.route('/polling/<key>')
def polling(key):
obj = BytesIO()
try:
s3.download_fileobj('carusoapi', key, obj)
s3.delete_object(Bucket='carusoapi', Key=key)
return send_file(obj, as_attachment=True, attachment_filename=key)
except Exception:
return 'File not ready yet', 204
I've seen some examples here but don't understand how to apply them or if that's even what I'm looking for.
I also noticed that boto3 S3 module has options like callback for download_fileobj here and you can specify chunksize here, but again, I don't understand how to apply this to a Flask response.
I know of a way to solve this that involves sending a signed download link to the client to download the item, but then I would have to implement in the client to delete the file.

Postman, Python and passing images and metadata to a web service

this is a two-part question: I have seen individual pieces discussed, but can't seem to get the recommended suggestions to work together. I want to create a web service to store images and their metadata passed from a caller and run a test call from Postman to make sure it is working. So to pass an image (Drew16.jpg) to the web service via Postman, it appears I need something like this:
For the web service, I have some python/flask code to read the request (one of many variations I have tried):
from flask import Flask, jsonify, request, render_template
from flask_restful import Resource, Api, reqparse
...
def post(self, name):
request_data = request.get_json()
userId = request_data['UserId']
type = request_data['ImageType']
image = request.files['Image']
Had no problem with the data portion and straight JSON but adding the image has been a bugger. Where am I going wrong on my Postman config? What is the actual set of Python commands for reading the metadata and the file from the post? TIA

Pardon the almost blog post. I am posting this because while you can find partial answers in various places, I haven't run across a complete post anywhere, which would have saved me a ton of time. The problem is you need both sides to the story in order to verify either.
So I want to send a request using Postman to a Python/Flask web service. It has to have an image along with some metadata.
Here are the settings for Postman (URL, Headers):
And Body:
Now on to the web service. Here is a bare bones service which will take the request, print the metadata and save the file:
from flask import Flask, request
app = Flask(__name__)
# POST - just get the image and metadata
#app.route('/RequestImageWithMetadata', methods=['POST'])
def post():
request_data = request.form['some_text']
print(request_data)
imagefile = request.files.get('imagefile', '')
imagefile.save('D:/temp/test_image.jpg')
return "OK", 200
app.run(port=5000)
Enjoy!

Make sure `request.files['Image'] contains the image you are sending and follow http://flask.pocoo.org/docs/1.0/patterns/fileuploads/ to save the file to your file system. Something like
file = request.files['Image']
file.save('./test_image.jpg')
might do what you want, while you will have to work out the details of how the file should be named and where it should be placed.

How to Define Google Endpoints API File Download Message Endpoint

All the examples I can find on google endpoint api (e.g., tic-tac-toe sample) show strings, integers, enums, etc fields. None of the examples say anything about how to specify document (e.g., image or zip files) uploads or downloads using the API. Is this not possible?
If this is possible, can anyone share a code snippet on how to define google endpoint api on the server to allow downloads and uploads of files? For example, is there a way to set HTTPResponse headers to specify that an endpoint response will serve a zip file? How do we include the zip file in the response?
An example with python or php would be appreciated. If anyone from the endpoints-proto-datastore team is watching this discussion, please say whether or not file downloads are supported in endpoints at the moment. We hate to waste our time trying to figure this out if it is simply impossible. Thanks.
We are seeking a complete example for upload and download. We need to store the key for the uploaded file in our database during upload and retrieve it for download. The client app sends a token that the API needs to use to figure out what file to download. Hence, we would need to store the blob key generated during the upload process in our database. Our database would have the mapping between the token and the blob file's key.
class BlobDataFile(models.Model):
data_code = models.CharField(max_length=10) # Key used by client app to request file
blob_key = models.CharField()
By the way, our app is written in Django 1.7 with a mysql (modeled with models.Model) database. It is infuriating that all the examples for Google App Engine upload I can find is written for a standalone webapp Handlers (no urls.py/views.py solutions could be found anywhere). Hence, building a standalone uploader is as much of a challenge as writing the API code. If your solution has full urls.py/views.py example for uploading files and saving the blob_key in our BlobDataFile, it would be good enough for us.

f you use the blobstore use the get_serving_url function to read the images from url in the client, or use the messages.ByteField in the ResourceContainer and serialize the image with base64.b64decode
#the returned class
class Img(messages.Message):
message = messages.BytesField (1)
#The api class
#endpoints.api(name='helloImg', version='v1')
class HelloImgApi(remote.Service):
ID_RESOURCE = endpoints.ResourceContainer(
message_types.VoidMessage,
id=messages.StringField(1, variant=messages.Variant.STRING))
#endpoints.method(ID_RESOURCE, Img,
path='serveimage/{id}', http_method='GET', #ID is the blobstore key
name='greetings.getImage')
def image_get(self, request):
try:
blob_reader = blobstore.BlobReader(blob_key)
value = blob_reader.read()
return Img(message=value)
except:
raise endpoints.NotFoundException('image %s not found.' %
(request.id,))
APPLICATION = endpoints.api_server([HelloImgApi])
And this is the response (save it in the client with the proper format)
{
"message": "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}
in the client you can do this (in python for continuity)
import base64
myFile = open("mock.jpg", "wb")
img = base64.b64decode(value) #value is the returned string
myFile.write(img)
myFile.close()

Did you try converting the image to base64 string and send it as an argument of your request on the client side?
So you will be able to do that on the server side :
#strArg is the Base64 string sent from the client
img = base64.b64decode(strArg)
filename = 'someFileName.jpg'
with open(filename, 'wb') as f:
f.write(img)
#then you can save the file to your BlobStore

Serving HTTP client with versioned resource only if it has changed - using Flask

I am running a webserver based on Flask, which serves a resource being versioned (e.g. installation file of some versioned program). I want to serve my HTTP client with new resource only in case, it already does not have the current version available. If there is new version, I want the client to download the resource and install it.
my Flask server looks like this
import json
import redis
import math
import requests
from flask import Flask,render_template,request
app=Flask(__name__)
#app.route('/version', methods=['GET','POST'])
def getversion():
r_server=redis.Redis("127.0.0.1")
if request.method == 'POST':
jsonobj_recieve=request.data
data=json.loads(jsonobj)
currentversion=r_server.hget('version')
if data == currentversion:
#code to return a 'ok'
else:
#code to return 'not ok' also should send the updated file to the client
else:
return r_server.hget('version')
if __name__ == '__main__':
app.run(
debug=True,
host="127.0.0.1",
port=80
)
my client is very basic:
import sys
import json
import requests
url="http://127.0.0.1/version"
jsonobj=json.dumps(str(sys.argv[1]))
print jsonobj
r=requests.post(url,data=jsonobj)
I will likely have to recode the entire client, this is not a problem but I really have no idea where to start....

Requirements Review
have web app, serving a versioned resource. It can be e.g. file with an applications.
have client, which allows fetching the resource only in case, the version of resource on the server and what client has locally already available differ
the client is aware of version string of the resource
allow client to learn new version string if new version is available
HTTP like design of your solution
If you want to allow downloading an application only in case, the client does not have it already, following design could be used:
use etag header. This usually contains some string describing unique status of resource you want to get from that url. In your case it could be current version number of your application.
in your request, use header "if-none-match", providing version number of your application present at client. This will result in HTTP Status code 306 - Not Modified in case, your client and server share the same version of resource. In case it differs, you would simply provide the content of the resource and use it. Your resource shall also denote in etag current version of the resource and your client shall take note of it, or find new version name from other sources (like from the downloaded file).
This design follows HTTP principles.
Flask serving resource with declaring version in etag
This is focusing on showing the principle, you shall elaborate on providing real content of the resource.
from flask import Flask, Response, request
import werkzeug.exceptions
app = Flask(__name__)
class NotModified(werkzeug.exceptions.HTTPException):
code = 304
def get_response(self, environment):
return Response(status=304)
#app.route('/download/app')
def downloadapp():
currver = "1.0"
if request.if_none_match and currver in request.if_none_match:
raise NotModified
def generate():
yield "app_file_part 1"
yield "app_file_part 2"
yield "app_file_part 3"
return Response(generate(), headers={"etag": currver})
if __name__ == '__main__':
app.run(debug=True)
Client getting resource only, if it is new
import requests
ver = "1.0"
url = "http://localhost:5000/download/app"
req = requests.get(url, headers={"If-None-Match": ver})
if req.status_code == 200:
print "new content of resource", req.content
new_ver = req.headers["etag"]
else:
print "resource did not change since last time"
Alternative solution of web part using web server (e.g. NGINX)
Assuming the resource is static file, which updates only sometime, you shall be able configuring your web server, e.g. NGINX, to serve that resource and declaring in your configuration explicit value for etag header to the version string.
Note, that as it was not requested, this alternative solution is not elaborated here (and was not tested).
Client implementation would not be modified by that (here it pays back the design is following HTTP concepts).

There are multiple ways of achieving this but as this is a Flask app, here's one using HTTP.
If the version is OK, just return a relevant status code, like a 200 OK. You can add a JSON response in the body if that's necessary. If you return a string with flask, the status code will be 200 OK and you can inspect that in your client.
If the version differs, return the URL where the file is located. The client will have to
download the file. That's pretty simple using requests. Here's a typical example for downloading file by streaming requests:
def get(url, chunk_size=1024):
""" Download a file in chunks of n bytes """
fn = url.split("/")[-1] # if you're url is complicated, use urlparse.
stream = requests.get(url, stream=True)
with open(fn, "wb") as local:
for chunk in stream.iter_content(chunk_size=chunk_size):
if chunk:
f.write(chunk)
return fn
This is very simplified. If your file is not static and cannot live on the server (like software update patches probably shouldn't) then you'll have to figure out a way to get the file from a database or generate it on the fly.