473,231 Members | 1,944 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes and contribute your articles to a community of 473,231 developers and data experts.

Two ways to run Python programs from C#

kudos
127 Expert 100+
Some time ago we created an example of how you could use Python from C, both as a separate process and how you
could embed it and run it as part of your C program. Then we realised; perhaps people don't write C programs anymore,so we made the same example in Java. After looking at the bytes.com forum, we started to suspect that perhaps people use C# instead of Java and C.

So here we close the loop and present a C# version!

Installation

We use a Windows 7 computer, with python 2.7 installed. Since we are going to call Python from the command line,
add the path to this Python installation.

Normally, the Python installation is placed in:

C:\Python27

Then to make Python accessible from the command line, we go to control panel, system, advanced system setting and click on this. At the bottom of
this there is going to be an "Environment Variable" button. Click on this, and locate a variable named "Path". If it
isn't there make it, and add C:\Python27. If "Path" is present, we can put C:\Python27 first, but make sure that it ends with a ";"

In our Windows 7, a Visual Studio 10 Express is installed. If such a tool is not present, download and install it.

Process approach

Our idea is the following; We define the Python program in this as a string. This program is going to do two things; Take two numbers from the command line, then add the numbers together and print them out to screen.

The program below will first save the python program to disk (from C#), then it will be executed Python from C# as a process where the program we just saved as a file will be executed.

Expand|Select|Wrap|Line Numbers
  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Text;
  5. using System.Diagnostics; // Process
  6. using System.IO; // StreamWriter
  7. namespace ConsoleApplication1
  8. {
  9.     class Program
  10.     {
  11.         static void Main(string[] args)
  12.         {
  13.             // the python program as a string. Note '@' which allow us to have a multiline string
  14.             String prg = @"import sys
  15. x = int(sys.argv[1])
  16. y = int(sys.argv[2])
  17. print x+y";
  18.             StreamWriter sw = new StreamWriter("c:\\kudos\\test2.py");
  19.             sw.Write(prg); // write this program to a file
  20.             sw.Close();
  21.  
  22.             int a = 2;
  23.             int b = 2;
  24.  
  25.             Process p = new Process(); // create process (i.e., the python program
  26.             p.StartInfo.FileName = "python.exe";
  27.             p.StartInfo.RedirectStandardOutput = true;
  28.             p.StartInfo.UseShellExecute = false; // make sure we can read the output from stdout
  29.             p.StartInfo.Arguments = "c:\\kudos\\test2.py "+a+" "+b; // start the python program with two parameters
  30.             p.Start(); // start the process (the python program)
  31.             StreamReader s = p.StandardOutput; 
  32.             String output = s.ReadToEnd();
  33.             string []r = output.Split(new char[]{' '}); // get the parameter
  34.             Console.WriteLine(r[0]);
  35.             p.WaitForExit();
  36.  
  37.             Console.ReadLine(); // wait for a key press
  38.         }
  39.     }
  40. }
  41.  
IronPython approach

There is a cool project which is called IronPython. Just like Jython, which we discussed in the previous article, this is a version of Python that is a part of .net.

Download it from here:

http://ironpython.net/

Install it, and remember the directory where it was installed (which on my computer is : C:\Program Files\IronPython 2.7).

Start up a fresh Console application in Visual Studio, right click on the project to the right and select "Add reference...".

Add all the .dll files in the IronPython directory.

Now you are ready to create strings in C# that is Python programs, execute them in IronPython and basically remove the need for external programs, temporary files and processes. Compared to the Java and the C example, this is kind of simple.

Expand|Select|Wrap|Line Numbers
  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Text;
  5. using IronPython.Hosting; // make us use Python
  6.  
  7. namespace ConsoleApplication2
  8. {
  9.     class Program
  10.     {
  11.         static void Main(string[] args)
  12.         {
  13.  
  14.             int a = 1;
  15.             int b = 2;
  16.  
  17.             Microsoft.Scripting.Hosting.ScriptEngine py = Python.CreateEngine(); // allow us to run ironpython programs
  18.             Microsoft.Scripting.Hosting.ScriptScope s = py.CreateScope(); // you need this to get the variables
  19.             py.Execute("x = "+a+"+"+b,s); // this is your python program
  20.             Console.WriteLine(s.GetVariable("x")); // get the variable from the python program
  21.             Console.ReadLine(); // wait for the user to press a button
  22.         }
  23.     }
  24. }
  25.  
Execution time wise, IronPython seems to be a bit slower than using the process approach. But then again, if we are looking at the IronPython web page, the last update to IronPython seems to be over a year ago!
Aug 4 '13 #1
1 67257
How will the process know to start c:\\kudos\\test2.py with parameters a and b??
Sep 19 '18 #2

Sign in to post your reply or Sign up for a free account.

Similar topics

220
by: Brandon J. Van Every | last post by:
What's better about Ruby than Python? I'm sure there's something. What is it? This is not a troll. I'm language shopping and I want people's answers. I don't know beans about Ruby or have...
7
by: stormslayer | last post by:
Folks: I've been considering a shift to python. I currently use c++builder (borland) or perl. I do computational models / statistics programming, and was interested in python b/c it a. has...
6
by: Cameron Laird | last post by:
QOTW: "... why does Microsoft try so hard to protect its sources?" "To avoid embarrassment." -- Peter Maas and Grant Edwards http://groups.google.com/groups?frame=left&th=9a599152d8b23b54 ...
31
by: surfunbear | last post by:
I've read some posts on Perl versus Python and studied a bit of my Python book. I'm a software engineer, familiar with C++ objected oriented development, but have been using Perl because it is...
68
by: Lad | last post by:
Is anyone capable of providing Python advantages over PHP if there are any? Cheers, L.
26
by: Christoph Zwerschke | last post by:
You will often hear that for reasons of fault minimization, you should use a programming language with strict typing: http://turing.une.edu.au/~comp284/Lectures/Lecture_18/lecture/node1.html I...
34
by: nicolasfr | last post by:
Hi, I am a bit disapointed with the current Python online documentation. I have read many messages of people complaining about the documentation, it's lack of examples and the use of complicated...
9
by: J. Peng | last post by:
I just thought python's way of assigning value to a variable is really different to other language like C,perl. :) Below two ways (python and perl) are called "pass by reference", but they get...
0
by: david khan | last post by:
Hello, can anybody convert python code that read openstreetmap xml file from http://github.com/rory/python-osm/blob/master/pyosm.py i try to translate but with the lack of knowledge of python ,...
0
by: abbasky | last post by:
### Vandf component communication method one: data sharing ​ Vandf components can achieve data exchange through data sharing, state sharing, events, and other methods. Vandf's data exchange method...
0
by: stefan129 | last post by:
Hey forum members, I'm exploring options for SSL certificates for multiple domains. Has anyone had experience with multi-domain SSL certificates? Any recommendations on reliable providers or specific...
0
Git
by: egorbl4 | last post by:
Скачал я git, хотел начать настройку, а там вылезло вот это Что это? Что мне с этим делать? ...
1
by: davi5007 | last post by:
Hi, Basically, I am trying to automate a field named TraceabilityNo into a web page from an access form. I've got the serial held in the variable strSearchString. How can I get this into the...
0
by: MeoLessi9 | last post by:
I have VirtualBox installed on Windows 11 and now I would like to install Kali on a virtual machine. However, on the official website, I see two options: "Installer images" and "Virtual machines"....
0
by: DolphinDB | last post by:
The formulas of 101 quantitative trading alphas used by WorldQuant were presented in the paper 101 Formulaic Alphas. However, some formulas are complex, leading to challenges in calculation. Take...
0
by: DolphinDB | last post by:
Tired of spending countless mintues downsampling your data? Look no further! In this article, you’ll learn how to efficiently downsample 6.48 billion high-frequency records to 61 million...
0
by: Aftab Ahmad | last post by:
Hello Experts! I have written a code in MS Access for a cmd called "WhatsApp Message" to open WhatsApp using that very code but the problem is that it gives a popup message everytime I clicked on...
0
by: Aftab Ahmad | last post by:
So, I have written a code for a cmd called "Send WhatsApp Message" to open and send WhatsApp messaage. The code is given below. Dim IE As Object Set IE =...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.