How can I distribute an Electron app with Python - python

I have a Python web application that I want to wrap in Electron. The web application backend is a very slim Flask app that forwarded calls to a Python package that does the processing, and formats the results. We have a React frontend that talks to this backend. We also have a pip based installation, that runs the Flask backend and serves the frontend, so you can pip install run the server and use it from your browser. This is similar to how Pgadmin 4 works.
Since this application is only used by people on their own computers, and never installed on a server, I want to convert it into an Electron app. However, I couldn't figure out how to distribute this application in one setup for Windows, MacOS and Linux. I don't want the users to have to install Python on their computers.
How can I do that?

There is a couple of clues on how to do that, even though I'm still unsure whether all necessary python modules can be bundled easily.
I have a similar case, even though I just want to bundle a prototype in an electron application so I can send it to collaborators for evaluation, without any intent of shipping it to final users.
My list of hints:
https://github.com/matbloch/electron-flask
https://efficientcoder.net/connect-python-3-electron-nodejs-build-desktop-apps/
https://www.techiediaries.com/flask-electron-tutorial/

I really don't see why you need to throw electron in the mix, instead of just using your browser. I reckon that a barebone electron app that serves your page in a single window is going to be 50Mb. The key benefits of electron is that it lets you do system calls (access local files / devices), but if you are running flask you already have this ability.
Your main obstacle is how to distribute the flask app, specifically without installing python - and electron is not going to make things any easier to that respect. You should probably look at pyinstaller which lets you create executables that embed python.
Now, if you're talking of getting rid of python altogether, then indeed you could do that, nodejs has a rich set of libraries for everything os / db-related, even image processing, but it will lack in data science and processing. YMMV.

Related

Need advice on how to incorporate Python into an Azure, specifically an ASP.NET web application environment

Need advice on how to incorporate Python into an Azure ASP.NET web application environment. Please excuse this question but I am new to Azure and I'm not clear on how to proceed. Every option that I look into looks promising but they all seem to have their own issues. Below is a more thorough explanation but the deal is that I have an Azure account with all kinds of goodies, a full fledged ASP.NET (C#) web app running via App Service, I am new to Azure (but not Python), and I'm hoping to add Python functionality to this whole setup. In short:
I want to add Python to this setup mainly to run scheduled jobs and also to trigger Python code from ASP.NET web form submissions
ideally I want a solution that resembles a non-cloud setup. I know this sounds silly but I'm finding the cloud/Azure functionality to be nuanced and not straightforward. I want a place to put a bunch of Python scripts, run, edit, schedule and trigger them from ASP.NET
for example: I created a WebJob that runs manually and from the documentation it wasn't clear how it should be called. I just figured out that you need to POST with Basic Auth (and the credentials provided).
!Also, Azure CMD does NOT like files with 'underscore _' in them! You cannot submit a Web Job with a py file with an underscore nor can you write output with a file with an underscore
!Also, I don't see an option for this Web Job to run Python 3.6.4 (which I installed via extension). Right now it is using 2.7.15...
!Also, CRON expression in Azure has six *, not five plus a command. Again, more weird stuff to worry about
I tried these instructions but the updates to the web page's Web.config file breaks the ASP.NET web pages
ideally the most cost effective option
Any info is greatly appreciated
MORE DETAILED EXPLANATION
Currently I have an ASP.NET site running via Azure App Service and I would like to add Python scripts and possibly Flask/Rest functionality. Note that I am not expecting to serve any content via Python and will largely be running Python scripts either on a scheduled basis or call them from ASP.NET. As a matter of fact, and this is an important point, I'm hoping to have ASP.NET trigger/run a Python script when a web form is submitted. I realize that I could get a similar effect if I make a web call to a Rest api that is running Python. In any event, I can't tell if I should:
add a Python extension to the current App Service running the web page (I tried this) OR
I did install Python 3.6.4 and some packages via pip
These instructions were useful, however the updates to the web page's Web.config file breaks the ASP.NET web pages
set up a VM that will have all of the Python code (but how can I have the .NET web page(s) call the Python in the VM?) OR
use Azure functions (I'm completely new to this and must admit that I prefer to have my old school Python environment instead although I see the benefit of using functions. But how do you deal with logging and debugging?)
or what about a custom windows container (Docker)?
This requires installing VS Code and that is OK but I'm looking for a solution that another user can get into with as few interruptions as possible
The idea is to ramp up the use of Python although, like I said, I don't expect Python to be serving any of the web content. It will be used to run in the background and to run scheduled jobs. What is the most robust and hopefully easiest way to add Python functionality to Azure (most importantly in a way to be able to trigger/use Python from an App Service running .NET?)? I've searched online and stack overflow so far with interesting finds but nothing to my liking.
For example, the following link discusses how to schedule WebJobs. I just created a manual one and when I called the webhook I got the message: "No route registered for '/api/triggeredwebjobs/TestPython/run'" How to schedule python web jobs on azure
The Docker method looks very promising, however, I'm looking for a simple solution as there is another person who will be involved in all of this and he's busy with other projects
Thank you very much!
I found a solution, though I'm open to more info. Like I mentioned in my post, I used the 'add extension' tool to add Python 3.6.4 to my Azure (installed in D:\home\python364x64).
Then I installed a bunch of packages via pip, these installed into D:\home\python364x64\Lib\site-packages.
I created a Python folder in webpages\Python where I put my scripts.
Finally, in ASP.NET I used the Diagnostics.Process call to run my code in ~\webpages\Python\somecode_2.py
The main issue is that Azure came with Python 2.7.15 installed. And for some reason when my Python code got executed it was using 3.4 (where that version came from beats me). So for each script, I had to create an _2.py version where I simply did the following in order to call the original script via Python 3.6.4. Looks a little nasty but it works. So like I said, I would welcome more info for ways to do this better...
--
import os<br>
os.system("D:\\home\python364x64\python.exe SomePython.py {0}".format(add arguments here)

Python Web Server - mod_wsgi

I have been looking at setting up a web server to use Python and I have installed Apache 2.2.22 on Debian 7 Wheezy with mod_wsgi. I have gotten the initial page up and going and the Apache will display the contents of the wsgi file that I have in my directory.
However, I have been researching on how to deploy a Python application and I have to admin, I find some of it a little confusing. I am coming from a background in PHP where it is literally install what you need and you are up and running and PHP is processing the way it should be.
Is this the same with Python? I can't seem to get anything to process outside of the wsgi file that I have setup. I can't import anything from other files without the server throwing a "500" error. I have looked on Google and Bing to try to find an answer to this, but I can't seem to find anything, or don't know that what I have been looking at is the answer.
I really appreciate any help that you guys can offer.
Thanks in advance! (If I need to post any coding, I can do that, I just don't know what you guys would need, if anything, as far as coding examples for this...)
Python is different from PHP in that PHP executes your entire program separately for each hit to your website, whereas Python runs "worker processes" that stay resident in memory.
You need some sort of web framework to do this work for you (you could write your own, but using someone else's framework makes it much easier). Flask is an example of a light one; Django is an example of a very heavy one. Pick one and follow that framework's instructions, or look for tutorials for that framework. Since the frameworks differ, most practical documentation on handling web services with Python are focused around a framework instead of just around the language itself.
Nearly any python web framework will have a development server that you can run locally, so you don't need to worry about deploying yet. When you are ready to deploy, Apache will work, although it's usually easier and better to use Gunicorn or another python-specific webserver, and then if you need more webserver functionality, set up nginx or Apache as a reverse proxy. Apache is a very heavy application to use for nothing but wsgi functionality. You also have the option of deploying to a PaaS service like Heroku (free for development work, costs money for production applications) which will handle a lot of sysadmin work for you.
As an aside, if you're not using virtualenv to set up your Python environment, you should look into it. It will make it much easier to keep track of what you have installed, to install new packages, and to isolate an environment so you can work on multiple projects on the same computer.

Install-less python web app on headless CentOS 5.x-6.x

I have a Linux web application which installs a webserver, a database, digital certificates etc using a set of .sh scripts.
In order to simplify user interaction during installation such as entering passwords, certificate details and such, I want to create a GUI installer. After much deliberation, following are some decisions and related questions
The target systems may or may not have a Desktop or a monitor installed. So providing a web interface to the install process may be the way to go. User would copy the application to the target machine, start the webservice which would then expose a web interface to continue the install. Would Python be a good choice for this?
Since this is an installer itself, the requirements to run it must be practically nil. This requires
Use python's built in SimpleHTTPServer. This will be used the one time during installation and then be killed. Any caveats to using the default python web server?
Compile app into standalone binary using one of the Freezing utilities. We don't want to depend on the user having python on their system and have been asked to account for admins who've removed python due to whatever reason. Is this precaution necessary?
Any comments on the general approach or alternative options will be greatly appreciated.

What are some successful methods for deploying a Django application on the desktop?

I have a Django application that I would like to deploy to the desktop. I have read a little on this and see that one way is to use freeze. I have used this with varying success in the past for Python applications, but am not convinced it is the best approach for a Django application.
My questions are: what are some successful methods you have used for deploying Django applications? Is there a de facto standard method? Have you hit any dead ends? I need a cross platform solution.
I did this a couple years ago for a Django app running as a local daemon. It was launched by Twisted and wrapped by py2app for Mac and py2exe for Windows. There was both a browser as well as an Air front-end hitting it. It worked pretty well for the most part but I didn't get to deploy it out in the wild because the larger project got postponed. It's been a while and I'm a bit rusty on the details, but here are a few tips:
IIRC, the most problematic thing was Python loading C extensions. I had an Intel assembler module written with C "asm" commands that I needed to load to get low-level system data. That took a while to get working across both platforms. If you can, try to avoid C extensions.
You'll definitely need an installer. Most likely the app will end up running in the background, so you'll need to mark it as a Windows service, Unix daemon, or Mac launchd application.
In your installer you'll want to provide a way to locate a free local TCP port. You may have to write a little stub routine that the installer runs or use the installer's built-in scripting facility to find a port that hasn't been taken and save it to a config file. You then load the config file inside your settings.py and whatever front-end you're going to deploy. That's the shared port. Or you could just pick a random number and hope no other service on the desktop steps on your toes :-)
If your front-end and back-end are separate apps then you'll need to design an API for them to talk to each other. Make sure you provide a flag to return the data in both raw and human-readable form. It really helps in debugging.
If you want Django to be able to send notifications to the user, you'll want to integrate with something like Growl or get Python for Windows extensions so you can bring up toaster pop-up notifications.
You'll probably want to stick with SQLite for database in which case you'll want to make sure you use semaphores to tackle multiple requests vying for the database (or any other shared resource). If your app is accessed via a browser users can have multiple windows open and hit the app at the same time. If using a custom front-end (native, Air, etc...) then you can control how many instances are running at a given time so it won't be as much of an issue.
You'll also want some sort of access to local system logging facilities since the app will be running in the background and make sure you trap all your exceptions and route it into the syslog. A big hassle was debugging Windows service startup issues. It would have been impossible without system logging.
Be careful about hardcoded paths if you want to stay cross-platform. You may have to rely on the installer to write a config file entry with the actual installation path which you'll have to load up at startup.
Test actual deployment especially across a variety of firewalls. Some of the desktop firewalls get pretty aggressive about blocking access to network services that accept incoming requests.
That's all I can think of. Hope it helps.
If you want a good solution, you should give up on making it cross platform. Your code should all be portable, but your deployment - almost by definition - needs to be platform-specific.
I would recommend using py2exe on Windows, py2app on MacOS X, and building deb packages for Ubuntu with a .desktop file in the right place in the package for an entry to show up in the user's menu. Unfortunately for the last option there's no convenient 'py2deb' or 'py2xdg', but it's pretty easy to make the relevant text file by hand.
And of course, I'd recommend bundling in Twisted as your web server for making the application easily self-contained :).

Setting up a Python web development environment on OS X

I'm running Mac OS X Leopard and wanted to know what the easy way to setup a web development environment to use Python, MySQL, Apache on my machine which would allow me to develop on my Mac and then easily move it to a host in the future.
I've been trying to get mod_wsgi installed and configured to work with Django and have a headache now. Are there any web hosts that currently use mod_wsgi besides Google, so I could just develop there?
FWIW, we've found virtualenv [http://pypi.python.org/pypi/virtualenv] to be an invaluable part of our dev setup. We typically work on multiple projects that use different versions of Python libraries etc. It's very difficult to do this on one machine without some way to provide a localized, customized Python environment, as virtualenv does.
Most Python applications are moving away from mod_python. It can vary by framework or provider, but most development effort is going into mod_wsgi.
Using the WSGI standard will make your Python application server agnostic, and allow for other nice additions like WSGI middleware. Other providers may only provide CGI (which won't scale well performance wise), or FastCGI.
I've worked with Django using only the included server in the manager.py script and have not had any trouble moving to a production environment.
If you put your application in a host that does the environment configuration for you (like WebFaction) you should not have problems moving from development to production.
I run a Linux virtual machine on my Mac laptop. This allows me to keep my development environment and production environments perfectly in sync (and make snapshots for easy experimentation / rollback). I've found VMWare Fusion works the best, but there are free open source alternatives such as VirtualBox if you just want to get your feet wet.
I share the source folders from the guest Linux operating system on my Mac and edit them with the Mac source editor of my choosing (I use Eclipse / PyDev because the otherwise excellent TextMate doesn't deal well with Chinese text yet). I've documented the software setup for the guest Linux operating system here; it's optimized for serving multiple Django applications (including geodjango).
For extra added fun, you can edit your Mac's /etc/hosts file to make yourdomainname.com resolve to your guest Linux boxes internal IP address and have a simple way to work on / test multiple web projects online or offline without too much hassle.
What you're looking for is Mod_Python. It's an Apache-based interpreter for Python. Check it out here:
http://www.modpython.org/
Google App Engine has done it for you. Some limitations but it works great, and it gives you a path to hosting free.
Of course Mac OS X, in recent versions, comes with Python and Apache. However you may want to have more flexibility in the versions you use, or you may not like the tweaks Apple has made to the way they are configured. A good way to get a more generic set of tools, including MySQL, is to install them anew. This will help your portability issues. The frameworks can be installed relatively easily with one of these open source package providers.
Fink
MacPorts
MAMP
mod_wsgi is really, really simple.
Pyerweb is a really simple (~90 lines including comments/whitespace) WSGI-compliant routing-framework I wrote. Basically the WSGI API is just a function that gets passed environ, and wsgi_start_response, and it returns a string.
envrion is a dict with the request info, for example environ['PATH_INFO'] is the request URI)
wsgi_start_response which is a callable function which you execute to set the headers,:
wsgi_start_response(output_response, output_headers)
output_response is the string containing the HTTP status you wish to send (200 OK etc), and output_headers is a list-of-tuples containing your headers (for example, [("Content-type", "text/html")] would set the content-type)
Then the function returns a string containing your output.. That's all there is to it!
To run it, using spawning you can just do spawn scriptname.my_wsgi_function_nae and it will start listening on port 8080.
To use it via mod_wsgi, it's documentation is good, http://code.google.com/p/modwsgi/wiki/QuickConfigurationGuide and there is a django specific section
The up-side to using mod_wsgi is it's the standard for serving Python web-applications. I recently decided to play with Google App Engine, and was surprised when Pyerweb (which I linked to at the start of this answer) worked perfectly on it, completely unintentionally. I was even more impressed when I noticed Django applications run on it too.. Standardisation is a good thing!
You may want to look into web2py. It includes an administration interface to develop via your browser. All you need in one package, including Python.
Check out WebFaction—although I don't use them (nor am I related to / profit from their business in any way). I've read over and over how great their service is and particularly how Django-friendly they are. There's a specific post in their forums about getting up and running with Django and mod_wsgi.
Like others before me in this thread, I highly recommend using Ian Bicking's virtualenv to isolate your development environment; there's a dedicated page in the mod_wsgi documentation for exactly that sort of setup.
I'd also urge you to check out pip, which is basically a smarter easy_install which knows about virtualenv. Pip does two really nice things for virtualenv-style development:
Knows how to install from source control (SVN, Git, etc...)
Knows how to "freeze" an existing development environement's requirements so that you can create that environment somewhere else—very very nice for multiple developers or deployment.

Categories