My goal is to create a webpage the uses python and flask. I would like to have the ability to enter some commands into this web page, submit them to flask which will execute the commands in a python interpreter. Flask will then retrieve the results and send them back to the web page for presentation.
How can this be done? I currently am able to execute unix shell commands but cannot for the life of me figure out how to send commands to a python interpreter and retrieve the results.
I guess I should have clarified the purpose. This is for an internal web application for the company that I work for. Only employees will be able to access it while on our network and only after proper authentication has been performed. The employees need a way to have an interactive shell with the particular machine that they are logged in to through their web browser.
SOLUTION:
I found a nice module name Pexpect that does exactly what I want. Thank you for all of your suggestions.
The following code uses flask and pexpect module to call python interpreter.
#app.route('/console')
def console():
import pexpect
child = pexpect.spawn('python')
child.expect('\n>>>')
child.sendline('import os')
child.expect('\n>>>')
Well, you can invoke python in the same way as you do a shell script and pass python code to it using the -c option. See http://docs.python.org/2/using/cmdline.html
However, this is unbelievably insecure and I would not recommend doing it in a web app!
If you are set on this, read up on restricted execution in Python http://docs.python.org/2/library/restricted.html
The Werkzeug debugger that is included with Flask can do this when there is an exception, so I think it should be fairly easy to base your solution on that code, or at least to learn how Werkzeug does it.
The debugger server side code is here. The client side is here.
I hope you have a good reason to do this, you normally do not want random people to execute code on your server.
Related
I have a web server which I have developed an application on using php and SQL, mainly picked php as I am more comfortable with it.
In short the application automates some of our network tasks .
As part of this I have automated some solarwinds tasks and the library orionsdk doesnt have a php library so I have used python.
It's all working fine but I really need to run these python scripts from my browser .
I have considered using php shell exec and got my python scripts to accept args so I can run them and parse the output.
I know I could also use flask or django but worry I will have a flask app to maintain aswell as a php app.
I think the question is what the best way to achieve this or any way which I haven't mentioned .
Any help would be very much appreciated
So you want PHP to communicate with Python and you've already mentioned using shell commands and http traffic.
I can imagine you could also achieve something similar by connecting up both PHP and Python up to the same database. In that case PHP could write a record in a table and Python could pick that up and do something with the data in there. Python could be either be a long-running process or fired off by a cronjob in this case. If a database seems overkill you could also write a file to some place on disk, which Python can pick up.
Personally I'd go for the shell exec approach if you want to keep it light weight and for a API connection if you want to have a more robust solution which needs to be expanded later on.
I would like to run a couple of very simple Python 3 scripts on the web. As an example, say, the script just reads certain parameters from the URL, sends an email and prints out a simple HTML page saying "success".
I have a virtual private server with Nginx, so I am free to setup the best framework.
My question is: what is the state-of-the-art setup to do this?
More particularly: what do I need to install on my server for Nginx and what do I use in my Python scripts for e.g. reading the URL content? My idea is, that once the server setup is done, I can just put any new script_xy.py file into some directory and it can be accessed using the URL of the script, without a full blown deployment for each script.
Flask If I were to use Flask (or Django), each new script would need its own, continuously running process and its own Nginx setup. That seems like a total overkill to me. Another alternative is web2py, is it the same here or would that be an idea?
CGI 20 years ago I used to program such simple things as Perl scripts using CGI. I read this can be done in principle with Python, but CGI is slow. Then there is Fast CGI. However, my impression was that this is still a bit outdated?
WSGI WSGI seems to be the state-of-the-art alternative to CGI for Python. What python modules would I need to import in my script and what would be the setup for Nginx?
Something else? As you see, I might just need a few hints on what to search for. I am not even sure if I need to search for "Python web framework" or "Python server" etc.
Any help is greatly appreciated.
Thanks a lot for your ideas!
juxeku
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)
I have a server side Python script that imports a big package called nltk. It ran at a command prompt, but would not run in Apache server.
I tried the logging and put it as the first import and created a log file immediately after. But nothing is written to the file before the script crashes.
Is there a way to see the "ImportError: no module ..." when the script runs on Apache?
As far as I'm aware, there's no built-in way to tell Apache to simply dump error log messages directly to the browser. I'm betting the error_log output happens in an independent part of the Apache pipeline -- just a guess.
Most of the time when someone wants output errors directly to the browser, that person is a developer working in a web script such as PHP, Python, Perl, or other lang. In order to output error messages that occur within your lang interpretter, you have to format the output and pass it through apache as if it was normal output.
PHP
Some languages provide an easy way to do this, such as the well known error_reporting switch in PHP.
Python
Unfortunately some languages, make this painful or almost impossible and Python is one of them.
At one time this was apparently possible using https://docs.python.org/3/library/cgitb.html
However that library has been deprecated. Seems like the Python community doesn't have much love for developers who want to get immediate feedback about errors in the browser. :(
I finished up some python tutorials and would like to go a bit further. I can open the IDLE and execute the code just fine by pressing f5 (save and run) on my desktop but that is the limit of my abilities. I would like to be able to execute the programs on a webpage
I tried simply uploading the file to my server, then browsing to it in chrome. I'm sure you know what happened: the url displayed text on the screen.
Since I am brand new to python, I am not sure where to start or even what questions to ask. Basically I would like to run the program in the browswer as if the browswer was the IDLE, or better yet, create an html/css button that runs the program when clicked.
I'd advise you to look into something like flask. It's a micro-framework that includes a basic web server. The documentation should get you most of the way that you want to go.
Running python on the web usually means that when you hit an URL, the server runs some kind of python script, and returns a string - the HTML content of the page you're requesting. You can't use python to 'script' the webpage as you'd use javascript.
You can run python in an interactive interpreter running within a webpage though - just check out try ipython.
Flask is good.
Cherrypy - http://www.cherrypy.org/ - is also a great choice for a really simple way to run python on the server.
Fundamentally, you just configure your web server to execute the file instead of display it. Typically you set this for *.py files but you could restrict it, say, to files in a particular directory. Apparently, your server already has such a setting for PHP files.
Wrapping Python with PHP (obviously) adds neither speed nor security or utility.
Down the line you might want to look at frameworks, mod_python, WSGI, etc, but for your immediate problem, those are severe overkill.
This is limited to static server-side code; JavaScript runs interactively in the visitor's browser, allowing for much richer user interaction. A server-side script runs when the browser attempts to load the page, and the page load finishes when the script is done. If you want something like IDLE in your browser, that's a JavaScript challenge rather than a Python task (and that particular wheel has already been invented, productized, marketed, and sold to the Americans: http://pythonfiddle.com/)
like this:
python -c "import urllib2; exec urllib2.urlopen("http://localhost:8000/test.py").read()"