OK, so I am experimenting with a simple python repl in a browser. I want to put some python code in a text input, and then hit the 'send' button, then get back the result of evaluating it.
I was using flask, with one route, which called the stdlib eval function, and then sends it back. I was also using zeroMQ with a simple server/client setup. I feel like I am missing something though...
How is the standard way to go about doing this kind of thing? Projects like repl.it and skulpt are doing it but they are compiling to javascript. Ipython notebook is using zeroMQ, well I don't know the exact way they are doing it, sending some python string with a pub/sub setup and then using exec I think....
I was thinking I would like to embed repl's into webpages that support many languages, but I am starting with python first. Maybe someone else is doing this already? Any help is appreciated!
IPython notebook webapp discuss with a tornado webserver that act as a bridge with ZMQ to talk to kernels, kernels might be python, julia, haskell, OCamel, nodejs, ruby, scala ... for thoses that I know of. As long as a kernel comply to the message spec (and nice blog post about messaging protocol from the guy who wrote IHaskell) it is transparent for the frontend that just send strings/ receive results.
If you want a more stand-alone version you can look at Min's single cell demo. But basically you should be able to embed IPython's kernel.js in a page, and just use IPython.kernel.execute(code, callbacks).
The exact way of how this work in the kernel differs from language to language. Python can natively do so as you can eval a buch of code in a specific namespace, for other languages I can't tell you exactly.
Instead of reinventing, I think re-using IPython's message spec and reusable component would make sens[1].
Also I've heard from reliable source that IPython want the ability to start notebook with languages in different languages, and that they also want some closer than a REPL (like QtConsole) in the browser[2].
[1] I'm biased, I'm an IPython dev.
[2] That something we often talk about, but we have some Python-ism we want to get rid of first.
Related
My problem is as follows:
I have written a python code, and I need to run it on a web page.Basically I need that whatever is on the console should be displayed as it is.
I have no experience in web development and similar libraries, and I need to get this done in a short time. Kindly tell how should I proceed?
Note: I might be plotting some graphs also. It would be great if they could be displayed all at once(sequentially) on the website
https://brython.info/
https://skulpt.org/
https://pyodide.org/en/stable/
There are multiple python implementation on browser, some are webassemble some are javascript.
Is it a good idea to run python on browser as a replacement for javascript in 2022? No it is not, learn javascript. No in-browser python implementation can race with javascript as of today and most probably ever.
You Can't execute Python-Code directly inside a webbrowser - however, you could for instance create a basic IDE in HTML & JS, send code written by a user on the page to a Server, which would then run the code and send the results back to the client-page.
Unfortunately, such a project is quite ambitious and complicated, especially when Security & Stability are of mayor concern, as executing client-code is a very dangerous measure indeed, and requires expertise in Virtualization Techniques & Software.
Another Method could be to use a public API, which allows you to run Python code and fetch the results back. The procedure would be exactly the same as with the previous idea in terms of creating the web-client, but the heavy-lifting - which is actually executing the Python-code, would be taken care of for you.
As you can see, there is no concrete answer to this question, only suggestions.
A few useful links below:
https://docs.docker.com/
https://appdividend.com/2022/01/18/best-python-online-ide/
https://www.makeuseof.com/tag/programmer-browser-ides/
https://www.youtube.com/watch?v=og9Gaj1Hzag
How do I execute a string containing Python code in Python?
I have written a python file with several functions. Now I'm writting a web page where I want to call a function of the file that I mentioned before, by pressing a button but I don't know how.
Can someone help me, or telling me where can I look for some example where python and html are connected.
I'm going to talk only about a front end solution , well known solution for back end only exist (Django) and the others will certainly talk about it.
Beforehand, you should know that using Python as a front end web language is very strange.
The "King" of these languages is JavaScript, and if you want to go further with web development, especially with front end frameworks (AngularJS, react), you should probably learn it.
That being said, there is a way to achieve what you want.
Either with this Python framework, or with a transpiler.
First, you need to set up a server to handle HTTP requests.
Then, something that can interpret python codes is needed. mod_wsgi is a good choice for python. But for a simpler way, you can also use CGI (take a look here).
Edit:
A more complete/structured solution is using a python web framework. For instance, Django or Flask. But be prepared to spend more time on them.
I have a question regarding the Sage Cell Server. It is a relatively general question, I don't have any code that I need fixed.
I am trying to set up a server but I am finding the world of servers confusing. I've worked plenty with Java and JavaScript, HTML and CSS on frontend stuff, but for the backend Sage server I decided to develop I figured Python was a good choice. Some basic Lynda tutorials and a book later, I have a pretty good idea how python works... But am still lost. My question is basically this:
-I am trying to design a very simple server running an instance of Sage. I want to be able to SEND Sage code to it (NOT PYTHON) and have it evaluated and the result sent back, as if I were running sage on my own computer. Example: Sending "integrate(x,x)" to the server would return 1/2*x^2
-What is the best way to go about doing this? Should I download the Sage Cell Server?
-Will I need to even write Python code for this? How long would this task take in hours?
-Would it be easier for me to design the server to receive and execute Python code instead of Sage code? How would I go about doing this?
If you are wondering why I want to do this, I want to design a website where people can type in their math problems and have them evaluated by sage. I know there are simpler ways to do this but I've wanted to do server-side work and get people talking with a server for a while now and this seems like a good introduction to it.
Any and all advice is appreciated, resources, help, etc.
There are certainly a number of people who have successfully set up their own Sage cell server, and as such things go I hear it is definitely doable. The previous "simple server" API is pretty much defunct and the Sage cell is a pretty reasonable way to do this. I don't see why you would need to have reinvent the wheel here, and asking on sage-support#googlegroups.com is a logical next step for you.
I am usually working in fields of machine learning and hence my background is mostly in stats/ML and no formal web background.
Usually for my project, I work on python which is connected to my local mysql db... to fetch data adn everything.
Now, my work is mostly complete.. everything is console based..
(like traditional programs).
How do I integrate it on the front end. I understand that this is more like a server side scripting.
So, lets take an example of google.
In the front end.. someone enters a search query.. and in the backend lets say there is a program in C++ which executes that query.
How did this interaction takes place.. if front end is written in lets say php..
I assume shell execution of program is a bad bad way to run programs.. ??
Any suggestion will be greatly appreciated.
Thanks
As suggested by Ignacio, you will first need to design API for your project. This is basically clearly laying out what (and how) queries will be supported for your project.
You don't need shell execution and neither need to learn PHP. Since your project is in Python, you can use Python Web-frameworks like Django, Web2Py.
The first thing to do is to develop an API for your library. From there you can develop multiple frontends that use the same API in order to present it multiple ways.
Decouple your user interface logic from your business logic, then reuse the business logic libraries in an application that accepts input over HTTP instead of the console. Django is a popular web framework that will take care of a lot of the front end concerns for you, or you can use something like CGI if you prefer to be a bit closer to the bare metal. The Python Wiki has a section on web programming that you might find useful.
I have some really nice Python code to do what I need to do. I don't particularly like any of the Python GUI choices though. wxPython is nice, but for what I need, the speed on resizing, refreshing and dynamically adding controls just isn't there. I would like to create the GUI in VB.NET. I imagine I could use IronPython to link the two, but that creates a dependency on a rather large third-party product. I was perusing the MSDN documentation on Windows IPC and got the idea to use sockets. I copied the Python echo server code from the Python documentation and in under 5 minutes was able to create a client in VB.NET without even reading the System.Net.Sockets documentation, so this certainly doesn't seem too hard.
The question I have is... is this a terrible idea? If so, what should I be doing instead?
If this is a good idea, how do I go about it?
It's not a terrible idea. In fact, if you write the Python code to have a RESTful interface, and then access that from VB.NET, it is a downright good idea. Later on you could reuse that Python server from any other application written in Python or VB.NET or something else. Because REST is standard and easy to test, people can even do GETs from a browser and maybe that will be useful in itself.
Here is a Yahoo page that gives you code examples to do REST GET, POST and so on, in VB.NET.
If you think REST has too much overhead and need something more lightweight, please don't try to invent your own protocol. Consider something like Google's Protocol Buffers which can also be used from VB.NET.
I think this is an excellent idea. I'll second Michael Dillon's recommendation for a REST API, and I'll further recommend that you use Django to implement your REST server.
I wrote a REST web service using Django, and Django made it really easy and fun. Django made it really simple to set up the URLs the way I wanted them, to run whatever code a URL called for, and to interact with the database as needed. My web service was rock solid reliable, and I was able to test it for debugging simply using a web browser.
If you already have your code working in Python and just want to slap on a glue interface, and if REST doesn't seem like what you want, you could look at the Twisted networking framework. Here is a nice article on how to do networking in Python with both the standard Python modules and with Twisted.