Develop Reference

c# and libraries from python

Does C# have a library that can reproduce the same thing?
from tensorflow import keras
from tensorflow.keras import layers
Functions to reproduce:
# A utility function to decode the output of the network
def decode_batch_predictions(pred):
input_len = np.ones(pred.shape[0]) * pred.shape[1]
# Use greedy search. For complex tasks, you can use beam search
results = keras.backend.ctc_decode(pred, input_length=input_len, greedy=True)[0][0][:, :max_length]
# Iterate over the results and get back the text
output_text = []
for res in results:
res = tf.strings.reduce_join(num_to_char(res)).numpy().decode("utf-8")
output_text.append(res)
return output_text
The situation is as follows. I trained the model, it works fine. But I haven 't found a way to decode the model 's response in the environment yet .NET ;(
I will be grateful for any help.

Communication between Python and C#

I have a Python backend running machine learning algorithms. I want to use the same backend for both an Excel plugin (C#) and a website. I want both interfaces to send my training data (thousands of lines of numbers in arrays) to the same Python application and retrieve the results in the form of another array up to a few thousand lines.
The website would fetch data from a SQL database and send that data to Python, while the Excel plugin would take the data that is in the current worksheet and send that data to Python. I need to be able to create numpy arrays in Python before continuing to process the data. Note that the website would be running on the same machine where the Python application resides. I still haven't decided what I will use to code the website, but I was leaning towards Node.js.
I have done some research and found a few options:
1- Named pipes
2- Sockets
3- RPC server such as gRPC or XML-RPC.
4- Writing the data to a file and reading it back in Python
5- Web Service
Note: I would need the Python "server" to be stateful and keep the session running between calls. So I would need to have a kind of daemon running, waiting for calls.
Which one would you experts recommend and why? I need flexibility to handle several parameters and also large arrays of numbers. Using IronPython is not an option because I am running Keras on Python, which apparently does not support IronPython.

I had the same problem recently.
I used a named pipe to transport data from python to my c# server, hope it helps you.
Python:
import win32pipe, win32file
class PipeServer():
def __init__(self, pipeName):
self.pipe = win32pipe.CreateNamedPipe(
r'\\.\pipe\\'+pipeName,
win32pipe.PIPE_ACCESS_OUTBOUND,
win32pipe.PIPE_TYPE_MESSAGE | win32pipe.PIPE_READMODE_MESSAGE | win32pipe.PIPE_WAIT,
1, 65536, 65536,
0,
None)
#Carefull, this blocks until a connection is established
def connect(self):
win32pipe.ConnectNamedPipe(self.pipe, None)
#Message without tailing '\n'
def write(self, message):
win32file.WriteFile(self.pipe, message.encode()+b'\n')
def close(self):
win32file.CloseHandle(self.pipe)
t = PipeServer("CSServer")
t.connect()
t.write("Hello from Python :)")
t.write("Closing now...")
t.close()
For this code to work you need to install pywin32 (best choice is from binarys): https://github.com/mhammond/pywin32
C#-Server:
using System;
using System.IO;
using System.IO.Pipes;
class PipeClient
{
static void Main(string[] args)
{
using (NamedPipeClientStream pipeClient =
new NamedPipeClientStream(".", "CSServer", PipeDirection.In))
{
// Connect to the pipe or wait until the pipe is available.
Console.Write("Attempting to connect to pipe...");
pipeClient.Connect();
Console.WriteLine("Connected to pipe.");
Console.WriteLine("There are currently {0} pipe server instances open.",
pipeClient.NumberOfServerInstances);
using (StreamReader sr = new StreamReader(pipeClient))
{
// Display the read text to the console
string temp;
while ((temp = sr.ReadLine()) != null)
{
Console.WriteLine("Received from server: {0}", temp);
}
}
}
Console.Write("Press Enter to continue...");
Console.ReadLine();
}
}

You can use Python for .NET (Python.NET). It may require some changes to your code, but then it should work very well, once everything is in good shape.
Python.NET allows two-way communication between CPython and CLR.

Let me give you a neat and quick recipe, in the form of example code.
There are basically two ways to tie python in the backend of C# (or a C# winform app or gui or something similar).
Method1: Iron Python. In this method you install a .net package in your visual studio called IronPython. I would not prefer this, because assuming your machine learning model uses keras or a lot of other libraries. It would be another quest to get you installations ready and working in IronPython. And most importantly, it is not as good as your common virtual env or conda environment.
Method2: (The Good Method): Create a Custom Process in your C# that takes arguments from your GUI, knows the path to your script and your python env. Using all these things, it calls your python code exactly the way you would call it in your terminal and pass arguments to it.
Now the tasty example code (I have used this simple trick and it always helps make my black screen python stuff look good with the cover of C# apps).
Python Part
import sys
a = sys.argv[1]
b = sys.argv[2]
print("The Sum = ", float(a)+float(b))
The C# Part
So here is the python process/function that you need to call on the click event of your sum button in the application
static void PythonProcess()
{
//1) Create Process Info
var psi = new ProcessStartInfo();
//Conda Env Path
psi.FileName = #"C:\Users\jd\.conda\pkgs\py\python.exe";
//2) Provide Script and the Arguments
var script = #"C:\Users\jd\Desktop\script.py";
var a = "15";
var b = "18";
psi.Arguments = $"\"{script}\" \"{a}\" \"{b}\"";
//3) Process Configuration
psi.UseShellExecute = false;
psi.CreateNoWindow = true;
psi.RedirectStandardOutput = true;
psi.RedirectStandardError = true;
//4) Execute Process and get Output.
var errors = "";
var results = "";
using(var process = Process.Start(psi))
{
errors = process.StandardError.ReadToEnd();
results = process.StandardOutput.ReadToEnd();
}
//5) Display Output
Console.WriteLine("ERRORS: ");
Console.WriteLine(errors);
Console.WriteLine();
Console.WriteLine("RESULTS: ");
Console.WriteLine(results);
}

Calling Python from C# is easily possible via Pyrolite where your Python code is running as a Pyro4 server. It should be fast enough to handle "large arrays of numbers" however you didn't specify any performance constraints.

I had the same issue and seem to end up with named pipes. Here is a nice example of how to set it up to talk C# => Python, assuming C# is the server.
It can use the same way to talk back or just Python.net to call directly through CLR as shown here. I use the latter.

How to call API using C#?

I am not a c# guy. Needless to say that I don't have experience on this topic.
I bought a software and I installed it on my computer. Now I thought of using some of it's functions on my software(that I make to plan in c#). So I messaged the person who sold me the software and he send me a two page pdf file explaining what to do.
It states:
This software features a COM interface.
And it goes saying it's API contains a function "stackAPI".
and the parameters used are apiname type string, apipass type string.
Return values type long. 0 for sucess and 1 for error.
That's all it states, I tired searching google, it could not help me at all. So how do I start?
when I write the following code on c# it gives me error.
string[] apiname;
string[] apipass;
stackAPI(apiname, apipass);
I know if I was using dll I would import it as
[DllImport("example.dll"]
But no dll is provided.
Do I need to add the path to the folder where the software is installed to call the API ?

To get started:
using example.dll;
Then in your main class:
example.CustomService api = new example.CustomService();
var response = api.Dostuff();
Console.WriteLine(response);

If anyone wants to know how I did it. After a week of searching I was able to find the solution today. I wanted to call the function stackAPI(apiname, apipass);.
stackAPI(apiname, apipass) was the member of stack.callapi
So I wrote:
dynamic lifestohack = Activator.CreateInstance(Type.GetTypeFromProgID("stack.callapi"));
than just you can call the function like this.
int rv;
string[] apiname;
string[] apipass;
rv=lifestoahck.stackAPI(apiname, apipass);
Hope it may help someone.

Using Javascript for Google Maps API from WPF

I am creating an application that interfaces with Google's Maps API v3. My current approach is using a WebBrowser control by WebBrowser.Navigate("Map.html"). This is working correctly at the moment; however, I am also aware of WebBrowser.InvokeScript(). I have seen this used to execute a javascript function, but I would like to have something like the following structure:
APICalls.js - Contains different functions that can be called, or even separated out into a file for each function if necessary.
MapInterface.cs
WebBrowser.InvokeScript("APICalls.js", args) - Or control the javascript variables directly.
I have seen the InvokeScript method used, but none of the examples gave any detail to the source of the function, so I'm not sure if it was calling it from an html file or js file. Is it possible to have a structure like this, or a similarly organized structure, rather than creating an html file with javascript in each one and using Navigate()?
Additionally, are there any easier ways to use Google Maps with WPF. I checked around, but all of the resources I found were at least 2-3 years old, which I believe is older than the newest version of the maps API.

I can't suggest a better way of using Google Maps API with WPF (although I'm sure it exists), but I can try to answer the rest of the question.
First, make sure to enable FEATURE_BROWSER_EMULATION for your WebBrowser app, so Google Maps API recognizes is it as modern HTML5-capable browser.
Then, navigate to your "Map.html" page and let it finish loading. Here's how it can be done using async/await (the code is for the WinForms version of WebBrowser control, but the concept remains the same).
You can have your APICalls.js as a separate local file, but you'd need to create and populate a <script> element for it from C#. You do it once for the session.
Example:
var scriptText = File.ReadAllText("APICalls.js");
dynamic htmlDocument = webBrowser.Document;
var script = htmlDocument.createElement("script");
script.type = "text/javascript";
script.appendChild(htmlDocument.createTextNode(scriptText));
htmlDocument.body.appendChild(script);
Then you can call functions from this script in a few different ways.
For example, your JavaScript entry point function in APICalls.js may look like this:
(function() {
window.callMeFromCsharp = function(arg1, arg2) {
window.alert(arg1 + ", " +arg2);
}
})();
Which you could call from C# like this:
webBrowser.InvokeScript("callMeFromCsharp", "Hello", "World!");
[UPDATE] If you're looking for a bit more modular or object-oriented approach, you can utilize the dynamic feature of C#. Example:
JavaScript:
(function() {
window.apiObject = function() {
return {
property: "I'm a property",
Method1: function(arg) { alert("I'm method 1, " + arg); },
Method2: function() { return "I'm method 2"; }
};
}
})();
C#:
dynamic apiObject = webBrowser.InvokeScript("apiObject");
string property = apiObject.property;
MessageBox.Show(property);
apiObject.Method1("Hello!");
MessageBox.Show(apiObject.Method2());

C# code completion with NRefactory 5

I just found out about NRefactory 5 and I would guess, that it is the most suitable solution for my current problem. At the moment I'm developing a little C# scripting application for which I would like to provide code completion. Until recently I've done this using the "Roslyn" project from Microsoft. But as the latest update of this project requires .Net Framework 4.5 I can't use this any more as I would like the app to run under Win XP as well. So I have to switch to another technology here.
My problem is not the compilation stuff. This can be done, with some more effort, by .Net CodeDomProvider as well. The problem ist the code completion stuff. As far as I know, NRefactory 5 provides everything that is required to provide code completion (parser, type system etc.) but I just can't figure out how to use it. I took a look at SharpDevelop source code but they don't use NRefactory 5 for code completion there, they only use it as decompiler. As I couldn't find an example on how to use it for code completion in the net as well I thought that I might find some help here.
The situation is as follows. I have one single file containing the script code. Actually it is not even a file but a string which I get from the editor control (by the way: I'm using AvalonEdit for this. Great editor!) and some assemblies that needs to get referenced. So, no solution files, no project files etc. just one string of source code and the assemblies.
I've taken a look at the Demo that comes with NRefactory 5 and the article on code project and got up with something like this:
var unresolvedTypeSystem = syntaxTree.ToTypeSystem();
IProjectContent pc = new CSharpProjectContent();
// Add parsed files to the type system
pc = pc.AddOrUpdateFiles(unresolvedTypeSystem);
// Add referenced assemblies:
pc = pc.AddAssemblyReferences(new CecilLoader().LoadAssemblyFile(
System.Reflection.Assembly.GetAssembly(typeof(Object)).Location));
My problem is that I have no clue on how to go on. I'm not even sure if it is the right approach to accomplish my goal. How to use the CSharpCompletionEngine? What else is required? etc. You see there are many things that are very unclear at the moment and I hope you can bring some light into this.
Thank you all very much in advance!

I've just compiled and example project that does C# code completion with AvalonEdit and NRefactory.
It can be found on Github here.

Take a look at method ICSharpCode.NRefactory.CSharp.CodeCompletion.CreateEngine. You need to create an instance of CSharpCompletionEngine and pass in the correct document and the resolvers. I managed to get it working for CTRL+Space compltition scenario. However I am having troubles with references to types that are in other namespaces. It looks like CSharpTypeResolveContext does not take into account the using namespace statements - If I resolve the references with CSharpAstResolver, they are resolved OK, but I am unable to correctly use this resolver in code completition scenario...
UPDATE #1:
I've just managed to get the working by obtaining resolver from unresolved fail.
Here is the snippet:
var mb = new DefaultCompletionContextProvider(doc, unresolvedFile);
var resolver3 = unresolvedFile.GetResolver(cmp, loc); // get the resolver from unresolvedFile
var engine = new CSharpCompletionEngine(doc, mb, new CodeCompletionBugTests.TestFactory(resolver3), pctx, resolver3.CurrentTypeResolveContext );
Update #2:
Here is the complete method. It references classes from unit test projects, sou you would need to reference/copy them into your project:
public static IEnumerable<ICompletionData> DoCodeComplete(string editorText, int offset) // not the best way to put in the whole string every time
{
var doc = new ReadOnlyDocument(editorText);
var location = doc.GetLocation(offset);
string parsedText = editorText; // TODO: Why there are different values in test cases?
var syntaxTree = new CSharpParser().Parse(parsedText, "program.cs");
syntaxTree.Freeze();
var unresolvedFile = syntaxTree.ToTypeSystem();
var mb = new DefaultCompletionContextProvider(doc, unresolvedFile);
IProjectContent pctx = new CSharpProjectContent();
var refs = new List<IUnresolvedAssembly> { mscorlib.Value, systemCore.Value, systemAssembly.Value};
pctx = pctx.AddAssemblyReferences(refs);
pctx = pctx.AddOrUpdateFiles(unresolvedFile);
var cmp = pctx.CreateCompilation();
var resolver3 = unresolvedFile.GetResolver(cmp, location);
var engine = new CSharpCompletionEngine(doc, mb, new CodeCompletionBugTests.TestFactory(resolver3), pctx, resolver3.CurrentTypeResolveContext );
engine.EolMarker = Environment.NewLine;
engine.FormattingPolicy = FormattingOptionsFactory.CreateMono();
var data = engine.GetCompletionData(offset, controlSpace: false);
return data;
}
}
Hope it helps,
Matra

NRefactory 5 is being used in SharpDevelop 5. The source code for SharpDevelop 5 is currently available in the newNR branch on github. I would take a look at the CSharpCompletionBinding class which has code to display a completion list window using information from NRefactory's CSharpCompletionEngine.