We Keep Coding

How can I call a python's local function from an HTML doc?

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.

A good Python web framework for existing console program?

I hope I'm asking on the right StackExchange site.
I've written a console program in Python onto which I'd like to put a web interface, but I'm having a hard time deciding what web framework to choose. I don't need much, but I'd like to avoid unnecessary work in trying to use it. I don't have a need for a database (for now), so that's not important to me at all.
I've looked at Django, Web2py, bottle.py, and web.py.
Django and Web2py seem to be great if I were starting out from scratch, but I'm not, and seems a little difficult to integrate into existing code.
bottle.py and web.py almost seem like they could work out, but they're so basic, I'm hoping there's something else out there that wouldn't require so much in the way of templating as these seem to do.
I don't simply want to make a carbon copy of the console interface put into a browser, but rather customize it for a web interface, so I'm not necessarily looking for anything that would simply wrap a console application into a web interface (although that would be interesting too.)

That's a sort of hard problem... Personally I don't see web.py as all that 'basic' as you put it. It should be really easy to wrap your code in some classes with GET and POST functions and be done.
Also, Django can be 'minified' as it were: How do I write a single-file Django application? is a whole conversation about this.
I would say, what is too 'basic' for you? You mentioned 'templating', but how would something magically template for you? There are open source templates for web apps, things like twitter bootstrap come to mind, that kind of give you a ready-made template for your next web app. Also YUI, and dojo do similar sorts of things (tho have a much different focus, since they are full blown JS frameworks).
That said, there is a brand new project called 'shovel' (here): https://github.com/seomoz/shovel
I haven't used it yet, but it seems to do the wrapping of commands into a web interface for you. which you said would be 'interesting'.
Personally I use web.py for all my web stuff.

I suggest Django. I've used Django both for simple mostly static sites and for sites with a lot of forms and I can't say Django imposes any restrictions or forces you to write hundreds LoC even for simple things. Instead you get nice auto generated administrative interface, built-in ORM, internationalization tools and many other things. Thereby, you have great opportunities to grow functionality of your app. In addition it has such vital thing as up-to-date documentation for every module.
Tutorial takes few hours and gives enough information to start developing full-blown sites.

Thanks the continuation which is implemented in the Nagare framework, you can develop a Web application like a console or desktop UI application: put the console code in a component.Task, then create some components for each interaction, i.e. some views that show the data that you print in your console application and receive some user input back. Then, the Nagare framework takes care of the rest: no need to declare URLS, to pass the context from a page to next...

PyQT can be handy if you are looking to implement it, to quote from the RiverBank PyQT website listed below:
"The QtWebKit module implements a web browser engine based on the WebKit open source browser engine used by Apple's Safari. It allows the methods and properties of Python objects to be published and appear as JavaScript objects to scripts embedded in HTML pages."
Source: http://www.riverbankcomputing.co.uk/software/pyqt/intro
Also, do not give up hope if that does not do the trick, as there is also "Pyjamas" which is very handy! Here is a brief description of it:
"Pyjamas is a Rich Internet Application (RIA) Development Platform for both Web and Desktop.
It contains a Python-to-Javascript compiler, an AJAX framework and a Widget Set API. Pyjamas started life as a Python port of Google Web Toolkit, the Java-to-Javascript compiler. Read the FAQ and the list of features."
source: http://pyjs.org
found via: google.com
I would say that when you are always looking to see what the best to use is, ask your question in google, and look on multiple sites and compare the top results of multiple sites to your question, also, it really depends on what you need and what your strong hand plays better in.

newbie: writing backend code for website

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.

Lightweight framework for forms w Ajax in Python

I'm new to Python and would like to know of some good framework / code library out there to help me out with building forms w/ ajax (and fallback to no-js) submits.
Doing it from scratch is possible ofcourse, but since this is such a common task I figured there must be some great stuff out there.
Django could be the way, but seems to big for this.
Thanks!

Are you looking for built-in AJAX support like Ruby on Rails? Or are you looking for a web framework that will work well with AJAX?
If you are looking for the latter, then Flask is a "micro framework" that is considerably smaller than Django. There are others such as web.py (again, very compact), Pylons and Turbogears but I guess you'd have already considered them.

Maybe not a direct answer but something definitely worth a look is the wonderful pyjamas http://pyjs.org/. That's a python to js compiler that lets you build whole browser client apps in python. If used with django as the server side (you only need the model and some views) then you get front-to-back python and a strong webservice model. For something simpler php with phpolait would be fine on the server side.

I personally made good experiences with web.py in conjunction with jQuery.
web.py (Python Webframework) is very lightweight and easy to understand, writing your own Ajax requests with jQuery is not too complicated either. I used these both in my first webproject written in Python and the learning curve was nearly zero. :)

Would it be a good idea or bad idea to connect a VB.NET frontend with a Python backend using sockets?

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.