Access variables from Go in Python and vise versa - python

My engine is written in GO and I already use SQLITE because I generate some plots that I want to display in a GUI. So far, I think that GO does not have a mature GUI package, so I am building my GUI in Python, with Tkinter that I am familiar with.
When I run my engine in GO with a certain flag, it calls the Python script for the GUI and it generates the content on the background continuously. There are certain modes that the GO engine runs and normally I have to change them by going back to the terminal that runs GO (different plots etc).
What I want, is to create action buttons in my Python GUI that they will change those flags/variables values and the GO script will generate different plots for example, without me going back to the terminal that runs the GO engine and manually do it.
So far, the only implementation from my side, was to create another SQLITE database and save my settings there. Then, when I press an action button at my GUI, it changes the value at my Settings Database and GO reads this value from there all the time, instead of waiting me to input it.
Is there any better way of doing it, passing a variable value(flag etc) from one programming language to the other(Python-GO) without using a database?
The variables that I am changing from the GUI are strings in general and I am asking this question because I think that it is a waste of resources to do it the way I do it.

Related

interacting with a user created gui dynamically using python

There is a user created GUI which is an .exe that loads a DLL. This GUI has a bunch of sliders, check boxes etc. I would like to move two sliders at the same time using python automatically without me using my mouse to move the sliders. I would like to know the python modules that an be used to achieve this purpose.
You can try using SikuliX.
It can be used to automate mouse or keyboard actions based on pattern matching. It is originally developed for Java I think, but it can be used with Python.
Basically, anything you can do yourself manually can be done with it.
The developer seems to be pretty active, so you can easily seek help from him if you have issues.

issues in coding programs without a user "save"

I'm a (relatively) novice programmer working in Python and Tkinter. The GUI app I'm building has many input fields, and all the data ultimately needs to end up in a file.
I'm wondering about the wisdom of trying to build this without a "save" button, so that it would operate like, say, Google Docs, in which the saving seems to happen more-or-less continuously. I'm worried about my (relatively computer-phobic) users assuming things are being saved to the file as they change various menu entries.
Specifically: is that just done via a background process saving every few seconds, with a save forced if the user tries to close between the auto-saves? Does one try to trigger the saves more intelligently than that? What are the issues?

Drag and Drop Files into Folders via Python GUI?

Problem
I'm trying to make a gui in python that displays two directories in two side-by-side panels and their contents (via tree, thumbnails, list, etc), which then allows the user to either:
drag files between both panels
select files to transfer (manually and via script), and transfer after user input
The point is to automate as much of the process as possible, but allow the user to verify each file's final transfer.
Is this possible? Which python gui library would be ideal for this? I'm just looking for a general direction, since I really don't know where to begin looking.
Current workaround
I have a python script that will sort mail into subfolders based on client, and then iterates through each client, simultaneously opening mail\<client> and the client's main file directory in explorer. I drag each file to its appropriate <main>\<client\<subfolder>, close the two windows, press 'enter' in IDLE, and it moves on to the next client. Tedious, but it's a rough implementation.
System info
Windows XP, Python 2.7
Well, you could implement a custom drag-and-drop with any GUI framework, so you might consider using Tkinter, since it's built-in to the standard Python library.
If you need to be able to drag-and-drop between applications, it's a bit more complicated, but supposedly can be achieved with Tkinter, although you might prefer to use wxPython, for which there's an example on the wiki.
For anything file related I would use the Python os module, http://docs.python.org/2/library/os.html

Daemonize, making program to work in background in python/wx.python

I created an complete logger-type program, that logs the certain data from the internet sources. It's GUI I coded in wx.python, now I want to daemonize it (if it is the right term). The program needs to run in background and user has to have option to call/open GUI when he pleases. How can I achieve this with wx.python?
I wouldn't really "daemonize" it per se. Instead, I would just put it in the system tray...at least, that's what I would do on Windows. I assume you can do something similar on the other OSes. Basically you want to bind the frame to wx.EVT_ICONIZE and in that method, you hide it. Then when the user double-clicks the taskbar icon, you want to show it and probably Raise it too.
There's some badly formatted code here: http://bytes.com/topic/python/answers/699757-wxpython-how-minimize-taskbar (I've used a variation of it myself, so I know it works).
And here's some information on Task bar icons: http://www.blog.pythonlibrary.org/2011/12/13/wxpython-101-creating-taskbar-icons/

Executing a python script in a subprocess - with graphics

I've seen a lot of stuff about running code in subprocesses or threads, and using the multiprocessing and threading modules it's been really easy. However, doing this in a GUI adds an extra layer of complication.
From what I understand, the GUI classes don't like it if you try and manipulate them from multiple threads (or processes). The workaround is to send the data from whatever thread you created it in to the thread responsible for the graphics and then render it there.
Unfortunately, for the scenario I have in mind this is not an option: The gui I've created allows users to write their own plotting code which is then executed. This means I have no control over how they plot exactly, nor do I want to have it. (Update: these plots are displayed in separate windows and don't need to be embedded anywhere in the main GUI. What I want is for them to exist separated from the main GUI, without sharing any of the underlying stack of graphics libraries.)
So what I'm wondering now is
Is there some clean(ish) way of executing a string of python code in a whole new interpreter instance with its own ties to the windowing system?
In response to the comments:
The current application is set up as follows: A simple python script loads a wxPython gui (a wx.App). Using this gui users can set up a simulation, part of which involves creating a script in plain python that runs the simulation and post-processes the results (which usually involves making plots and displaying them). At the moment I'm doing this by simply calling exec() on the script code. This works fine, but the gui freezes while the simulation is running. I've experimented with running the embedded script in a subprocess, which also works fine, right up until you try to display the created graphs (usually using matplotlib's show()). At this point some library deep down in the stack of wxPython, wx, gtk etc starts complaining because you cannot manipulate it from multiple threads.
The set-up I would like to have is roughly the same, but instead of the embedded script sharing a GUI with the main application, I would like it to show graphics in an environment of its own.
And just to clarify:
This is not a question about "how do I do multithreading/multiprocessing" or even "how do I do multithreading/multiprocessing within a single wxpython gui". The question is how I can start a script from a gui that loads an entirely new gui. How do I get the window manager to see this script as an entirely separate application?
The easiest way would be to generate it in a temporary folder somewhere and then make a non-blocking call to the python interpreter, but this makes communication more difficult and it'd be quite hard to know when I could delete the temp files again. I was hoping there was a cleaner, dynamical way of doing this.
Can you simply use subprocess to run 'python.exe' and pipe the script in?
Alternatively, the multiprocessing package should suffice if you want to move some (pickle-able) data over to the new process in which you run the script. Just create a function/callable that runs the script, and create a Process object with the callable as target. That way, you should be able to pass some data over, without having GUI issues.
Capturing text with either is easy, subprocess allows that and no more. With multiprocess, you can pass python objects back and forth more easily.
On Windows, you can create window with a parent window from another process, and draw to that.
See the hWndParent argument to CreateWindowEx.
If wxWindows supports getting/setting that explicitly, then you should be good to go.
Depending on your platform, something similar might be possible in any windows system.
So, just giving your users the ability to find the handle of your apps window should give them the option to plot away at views embedded in your app, while running in their own processes.
I don't no much about wx, I work with jython(python implemented in java and you can use java) and swing. Swing has its own worker thread, and if you do gui updates you wrap your code into a runnable and invoke it with swing.invokelater.
You could see if wx has something like that, if you however are only allowed to manipulate the gui from the thread in which you created it try something similar. create a proxy object for your gui, which forwards all your calls to your thread which forwards them to the gui.
But proxying like this gets messy. how about you let them define classes, with an 'updateGui' function, that they should hand back to you over a queue and that you will execute in your gui thread.
In wxPython land when you use threads, you have to use its thread-safe methods to communicate with the GUI: wx.CallAfter, wx.CallLater or wx.PostEvent. In your case, I would run any long running code in a separate thread/process and when it's done its processing, send the result to the GUI. The GUI can instantiate a new frame and use matplotlib or PyPlot to show the plot, depending on which way you want to go. I've heard you can draw the plot using FloatCanvas too.
Anyway, if you instantiate the new frame correctly, then you can instantiate N frames and show them and be fine. See the wxPython wiki for a few examples of using Threads with wx: http://wiki.wxpython.org/LongRunningTasks

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