I am looking for a 'sanity check' before I start working on this, as I'm new to writing server-side code. I want to stick to Python if possible, since that's what I'm used to!
I have written a desktop app (wxPython) that allows offsite employees to record their working times, the results of which they currently email to the company. I want to be able to have them save data directly to an 'online' location, from which the company can get summary data.
From what I have read (mostly here on StackOverflow) leads me to think I should do the following:
Run a database on the server with local access only (I'm favouring RethinkDB...)
Write a Python server app that can access the database but only exposes the functionality needed per user. Probably with different ports for users, payroll, and admin (me). Secure the sockets with TLS.
Add code to the desktop app to access the server.
Is this a good approach, or am I reinventing wheels and should learn to use Django or some other web framework?
As Paulo Almeida suggested in the comments making a REST application you interface with your wxPython application is probably the way to go. For this django may be a solution but it is probably an overkill microframework such as web.py, flask or bottle is enough and more easier to grasp
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I'm tasked with creating a web app (I think?) for my job that will tracker something in our system. It'll be an internal tool that staff uses to keep track of the status of one of the things we do. It should look like trello, with cards that drag from step to step. That frontend exists, but my job is to make the system update when the cards are dragged. This requires using an API in Python and isn't that complicated to grab from/update. I have no idea how to put all of this together. My job is almost completely nontechnical and there's no one internally who knows what I'm doing except for me. I'm in so over my head here and have no idea where to begin. Is this something I should deploy on Elastic Beanstalk? EC2? How do I tie this together and put it somewhere?
Are you trying to pull in live data from Trello or from your companies own internal project management tool?
An EC2 might be useful, but honestly, it may be completely unnecessary if your company has its own servers. An EC2 is basically just a collection of rental computers to help with scaling. I have never used beanstalk so my input would be useless there.
From what I can assume from the question, you could have a python script running to pull from the API and make the changes without an EC2.
First thing you should do is gather as much information about what the end product should look like. From your question, I have the feeling that you have only a vague idea of what the stakeholders want. Don't be afraid to ask more clarification about an unclear task. It's better to spend 30 minutes discussing and taking note than to show the end-product after a month and realizing that's not what your boss/team wanted.
Question I would Ask
Who is going to be using this app? (technical or non-technical person)
For what purpose is this being developed?
Does it need to be on the web or can it be used locally?
How many users need to have access to this application?
Are we handling sensitive information with this application?
Will this need to be augmented with other functionality at some point?
This is just a sample of what I would ask, during the conversation with the stakeholder a lot more will pop up for sure.
What I think you have to do
You need to make a monitoring system for the tasks that need to be done by your development team (like a Kanban)
What I think you already have
A frontend with the card that are draggable to each bin. I also assume that you can create a new card and delete one in the frontend. The frontend is most likely written in React, Angular or Vue.js. You might also have no frontend framework (a mix of jQuery and vanilla js), but usually frontend developper end up picking a framework of sort to help the development.
A backend API in Python (in Flask or with Django-rest-framework most likely) that is communicating with a SQL database like postgresql or a Document database like MongoDB.
I'm making a lot of assumption here, but your aim should be to understand the technology you will be working with in order to check which hosting would work best. For instance, if the database that is setup is a MySQL database you might have some trouble with some hosting provider.
What I think you are missing
Currently the frontend and the backend don't communicate to each other. When you drag a card it won't persist if you refresh the page. Also, all of this is sitting in your computer and cannot be used by any one from your staff. You need to first connect the frontend with the backend so that the application has persistance. Then you need to deploy this application somewhere so that it is reachable by your staff.
What I would do is first work locally to make sure that the layer of persistance is working. This imply having the API server, the frontend server and the database server running simultaneously on your computer to develop. You should then fetch data from the API to know which cards are there in the database and then create them visually in your frontend at the right spot.
When you drop a card to a new spot after having dragging it should trigger a POST request to your API server in order to update the status of this particular card (look at the documentation of your API to check what you need to send).
The server should be sending back an updated version of the cards status if the POST request was sucessful, so your application should then just redraw the card at the right spot (it won't make a difference for you since they are already at the right spot and your frontend framework will most likely won't act on this change since the state hasn't changed). That's all I would do for that part.
I would then move to the deployment phase to make sure that whatever you did locally can still work online. I would use Heroku to start instead of jumping directly to AWS. Heroku is a service built on top of AWS which manage a lot of the complexity of AWS for you. This is great for prototyping and it means that when your stuff is ready you can migrate to AWS easily and be confident that a setup exist to make your app work. You might also be tied up to your company servers, which is another thing I would ask to the stakeholder (i.e. where can I put this application and where I can't put it).
The flow for a frontend + api + database application on Heroku is usually as follow. You create a github repo for your frontend (make it private) and you create an app on Heroku that will watch this repository for changes. It will re-deploy the application for you when it sees a change at a specific subdomain of Heroku hosting. You will need to configure some procfiles that will tell Heroku what to do with a given application type. This is where you need to double check what frontend you are using since that might change the procfiles used. It's most likely a node.js based frontend (React, Angular or Vue) so head over here for the documentation of how to put that online.
You will need to make a repo for the backend also that is separate from the frontend, these two entities are distinct and they only communicate through HTTP request (frontend->backend) and JSON (backend->frontend). You will need to follow the same idea as with the frontend to deploy, head over here.
Once you have these two online, you need to create a database on Heroku. This is done by adding a datastore to your api, head over here. There are some framework specific configuration you need to do to make the API talk to an online database, but then you will need to find that configuration on the framework documentation. The database could also be already up and living on your server, if this is the case you just need to configure your online backend to talk to that particular database at a particular address.
Once all of the above is done, re-test your application to check if you get the same behavior as before. This is a usable MVP, however there are no layer of security. Anyone with the right URL could just fetch your frontend and start messing around with your data.
There is more engineering that need to be done to make this a viable end product. This leads us to my final remark: why you are not using a product like Trello, Jira, or even Github Project? If it is to save some money on not paying for a subscription I think you should factor in the cost of development, security and maintenance of this application.
Hope it helps!
One simple option is Heroku for deploy your API and your frontend application.
I want to create a desktop application written in python and using polymer as the front-end. To access the user interface, we use web browser such as chrome, mozilla, and safari. I did a lot of research in how to do this. The only reference I have is home Assistant, but I'm still don't quite understand about the architecture and the approach. Anyone have another solution or approach in how to do this?
python ships with a basic http server, however according to the docs it's not made for production use. But it's probably good enough for your use case (single user). On top of this you can implement a basic REST-Api and serve your frontend (.js/.html) as static content.
Or use a framework like django https://www.djangoproject.com/
Momentarily I am creating a python based application through the programme Ren'py. Now I have to couple the game with a SQL database. The admin on the board of the programme recommended using urllib to do this.
http://lemmasoft.renai.us/forums/viewtopic.php?f=8&t=29954
This is my thread. Now, I've managed to succesfully add the urllib to the program, but I'm lost at the entire "talk to a web service, which would then talk to the sqlite database" segment. Could you perhaps provide any hints/ tips?
I've never worked with Python before, so it's kind of challenging.
The answer you got on that forum isn't very helpful, in that the poster didn't really explain what they meant.
urllib is really the most minor component of the solution they're suggesting. What they actually mean is that you set up an entire web service, hosted on a URL somewhere, which talks to its own database. Your local installations of the app would then use a Python web library to communicate with that remote database over the web.
While this isn't particularly difficult, it is a fair amount of work, especially if you don't have any experience in doing this. You'll need a Python web framework and somewhere to host it. Since you talk about admins needing to log in and view data, you might want to explore Django, which comes with a built-in admin interface.
You'll then need to design an API to allow your Ren'py app to communicate with that web service, and you might want to look at the Django REST framework for that. The final part is getting your app to talk to the web service, which is where the recommendation of urllib comes in - but to be honest, that isn't even a very good recommendation here: the third-party library requests would be much better.
As I say, there's quite a lot of work. A much simpler solution would be to use Python's built-in sqlite3 library to talk to a local database via SQL, but that wouldn't do anything to make people's data available in a central location and would be open to anyone who worked out how to query the database.
I've published an iOS app using a local database stored directly on the user's device. What I'd like to do for my next app is have a central database on a remote server where users can asynchronously send/receive data. I'm relatively new to web service programming and I'm not sure where to start. I've purchased a server space on a web hosting site and have a MySql database/phpMyAdmin configuration on the server. I'm not sure how to handle the server side code. I know well enough that a database should never be exposed publicly over the internet for obvious security reasons. Therefore I need some kind of web service where my iOS/Android apps can query the service, the web service fetches data and sends it back to the clients in a XML or JSON format. I'd like to write the web service layer in python. I've done a little research and django seems to be recommended by some for these kinds of things. So, my questions are:
What are good resources for making a web service in python on a remote server.
What are the "best practices" for creating/debugging/testing the server side code. Should I try and make a local MySql database and write the server code locally and test and then push it to my remote server when it is finished?
My ultimate starting goal is some kind of proof of concept hello world app. Where from my iOS and android devices I can query the remote database going through the service layer and getting data back or inserting data.
Any tips or advise would be appreciated. I'm a noob in this area but ready to learn.
Too many general questions in one, so I'll just refer you.
I'd start with an awesome Designing Poetic APIs PyCon US 2014 talk.
Since you want to follow the REST principles with Django, take a look at the list of django packages available for writing RESTful apps: Applications that help you build a REST API.
Basically, the major "players" are:
django-tastypie
django-rest-framework
Also see:
What are the differences between django-tastypie and djangorestframework?
Choosing an API framework for Django
Hope that helps.
I'm looking for a bit of web development advice. I'm fairly new to the area but I'm sure there are some gurus out there willing to part with some wisdom.
Objective: I'm interested in controlling a Python application on my computer from my personal web hosted site. I know, this question has been asked several times before but in each case the requirements were a bit different from my own. To reduce the length of this post I'll summarize my objective in a few bullet points:
Personal site is hosted by a web hosting company
Site uses HTML, PHP, MySQL, Python and JavaScript, the majority of everything is coded by me from the ground up
An application that is coded in Python will run on a PC within my home and will communicate with an Arduino board
The app will receive commands from the internet to control actuation via the Arduino, and will transmit sensor data back to the site (such as temperature)
Looking for the communication to be bi-directional, fast and secure
Securing the connection between site and Python app would be most ideal
I'm not looking to connect to the Python application directly, the web server must serve as the 'middle man'
So far I've considered HTTP Post and HTML forms, using sockets (Python app would run as a web server), an IRC bot and reading/writing to a text file stored on the web server.
I was also hoping to have a way to communicate with the Python app without needing to refresh the webpage, perhaps using AJAX or JavaScipt? Maybe with Flash?
Is there something I'm not considering? I feel like I'm missing something. Thanks in advance for the advice!
Just thinking out loud for how I would start out with this. First, regarding the website itself, you can just use what's easiest to you, or to the environment you're in. For example, a basic PHP page will do just fine, but if you can get a site running in Python as well, I'd prefer using the same language all over.
That said, I'm not sure why you would need to use a hosted website? Given that you're already forced to have a externally accessible PC at home for the communication, why not run a webserver on that directly (Apache, Nginx, or even something like CherryPy should do)? That webserver can then communicate with the python process that is running to control your Arduino (by using e.g. Python's xmlrpclib). If you would run things via the hosting company, you would still need some process that can handle external requests securely... something a webserver is quite good at. Just running it yourself gives you all the freedom you want, and simplifies things by lessening the number of components in your solution.
The updates on your site I'd keep quite basic: commands you want to run can be handled in the request handlers of the webserver by just calling the relevant (xmlrpclib) calls. Dynamically updating the page is best done by some AJAX calls I reckon. Based on your story, these updates are easily put in a JSON object, suitable for periodically updating only the relevant segments of your page.