I want to pass an image object from my c# project to my python script however from my understanding whatever there is in the arguments it is considered as string and also when I try type(passedImage) in python it identifies it as a string even if I try to put a number instead of the image variable.
ProcessStartInfo start = new ProcessStartInfo();
start.FileName = #"C:\Python\Python36\python.exe";
start.Arguments = string.Format("{0} {1}", #"C:\OCRonImage2.py", image );
start.UseShellExecute = false;
start.RedirectStandardOutput = true;
start.CreateNoWindow = true;
using (Process process = Process.Start(start))
{
}
When executing OCRonImage2.py manually, is it an image file location that you would pass as an argument? I would be surprise if you would pass in a stream from the command line. It is no surprise that attempting to put the entire image's bytes into an argument would create a string too long. But with the error you reported, I would also believe that the python script was expecting a file path to the image. However, if you look at that python code, I wouldn't be surprised if you find it using the filepath argument to open the file, probably using Image.open(filepath,mode=r). Mode is optional, r is the default.
You are in luck however, Image.open also takes a stream. If you are willing to modify the python code there are two options:
Try converting the argument to a stream object, since the argument is a string maybe use io.StringIO()
Use input() instead of the argument passed, then you could redirect the input of the process and stream the file into your python.
ProcessStartInfo start = new ProcessStartInfo();
start.FileName = #"C:\Python\Python36\python.exe";
start.Arguments = string.Format("{0}", #"C:\OCRonImage2.py");
start.UseShellExecute = false;
start.RedirectStandardOutput = true;
start.RedirectStandardInput = true;
start.CreateNoWindow = true;
using (Process process = Process.Start(start))
{
StreamWriter streamWriter = process.StandardInput;
streamWriter.Write({imageString});
// ...
}
Be sure the way you encode imageString the same as the decoding is performed in the python script.
Hopefully one of these solutions will work for you.
As I work with the Anaconda distribution of Python, in my tests on an isolated conda environment, the OCR is successful with pytesseract through a Python script, on a test image.
Prerequisites to test:
install Anaconda and create an env called py3.7.4: conda create --name py3.7.4
activate the env with conda activate py3.7.4
install pytesseract with conda install -c conda-forge pytesseract
create a folder called Test and place a jpg file called ocr.jpg with the following sample image:
in the same Test folder also place a Python script called ocr_test.py with the following code:
import pytesseract
from PIL import Image
import argparse
parser = argparse.ArgumentParser(
description='perform OCR on image')
parser.add_argument("--path", "-p", help="path for image")
args = parser.parse_args()
print(pytesseract.image_to_string(Image.open(args.path)))
print("done")
The above snippet accepts the image path as a command line argument. The --path flag must be specified in order to pass the image path as an arg.
Now, in the C# code snippet below, we will:
launch the cmd shell
navigate to the workingDirectory Test folder by specifying the WorkingDirectory arg for the process.start() method.
activate Anaconda with the anaconda.bat file(replace the file path as per its location on your computer)
activate the above conda environment
call the Python script passing the imageFileName as an arg.
C# snippet:
using System.Diagnostics;
using System.Threading;
namespace PyTest
{
class Program
{
static void Main(string[] args)
{
string workingDirectory = #"C:\Test";
string imageFileName = "ocr.JPG";
var process = new Process
{
StartInfo = new ProcessStartInfo
{
FileName = "cmd.exe",
RedirectStandardInput = true,
UseShellExecute = false,
RedirectStandardOutput = false,
WorkingDirectory = workingDirectory
}
};
process.Start();
using (var sw = process.StandardInput)
{
if (sw.BaseStream.CanWrite)
{
// Vital to activate Anaconda
sw.WriteLine(#"C:\Users\xxxxxxx\Anaconda3\Scripts\activate.bat");
Thread.Sleep(500);
// Activate your environment
sw.WriteLine("conda activate py3.7.4");
Thread.Sleep(500);
sw.WriteLine($"python ocr_test.py --path {imageFileName}");
Thread.Sleep(50000);
}
}
}
}
}
If you have followed the above steps, you should receive the following output on executing the C# snippet in Visual Studio:
Output:
Microsoft Windows [Version 10.0.18362.535]
(c) 2019 Microsoft Corporation. All rights reserved.
C:\xxxxxxx\Projects\Scripts>C:\Users\xxxxx\Anaconda3\Scripts\activate.bat
(base) C:\xxxxxx\Projects\Scripts>conda activate py3.7.4
(py3.7.4) C:\xxxxxxx\Projects\Scripts>python ocr_test.py --path ocr.JPG
Introduction
This is a test to see accuracy of Tesseract OCR
Test 1
Test 2
done
Note: I am unable to test with a standalone Python distro but I believe it should work just fine with that too. The key is to pass the image file path as an argument to the Python script too. That way, the image file path passed as argument from C# is treated similarly by Python too. Also, using Image.open() does the following(from the docs):
Opens and identifies the given image file. This is a lazy operation;
this function identifies the file, but the file remains open and the
actual image data is not read from the file until you try to process
the data
You can save the image as a file somewhere on your local machine and give the python program the path to read it.
That's the easiest way I think you can do.
Edited: You can use a temporary file to make sure the file can be deleted in the future
http://www.java2s.com/Tutorial/CSharp/0300__File-Directory-Stream/Createatempfileanddeleteit.htm
http://www.vcskicks.com/temporary-file.php
I think this will be bad to pass IMAGE as Argument.
Good options to go with:
Stdin on your python example, and RedirectStandardInput on your c#.
TCP Communication. Using TCP Services (No Internet Needed)
Sharing Memory. (More Info, ReadyLib)
Related
Lets say I have this super Python script that needs to run cv2 in the future...
import cv2
def method():
print("Hello")
parameter = "l"
return "OOPS"
method()
And in C# something like this.
Process p = new Process();
p.StartInfo = new ProcessStartInfo(#"D:\Programming\Python\python.exe", fileName)
{
RedirectStandardOutput = true,
UseShellExecute = false,
CreateNoWindow = true
};
p.Start();
string output = p.StandardOutput.ReadToEnd();
But this does throw an error "ImportError: DLL load failed". Alright seems like it is lookin in wrong directories for libraries since I have about 4 Python interpreters. Follows quick fix.
string path = #"D:\Programming\Python;" + Environment.GetEnvironmentVariable("PATH", EnvironmentVariableTarget.Machine);
Environment.SetEnvironmentVariable("PATH", path, EnvironmentVariableTarget.Process);
Environment.SetEnvironmentVariable("PYTHONHOME", #"D:\Programming\Python;", EnvironmentVariableTarget.Process);
Environment.SetEnvironmentVariable("PYTHONPATH ", #"D:\Programming\Python\Lib; D:\Programming\Python\DLLs", EnvironmentVariableTarget.Process);
string fileName = #"..\Python\hello.py";
Process p = new Process();
p.StartInfo = new ProcessStartInfo(#"D:\Programming\Python\python.exe", fileName)
{
RedirectStandardOutput = true,
UseShellExecute = false,
CreateNoWindow = true
};
p.Start();
string output = p.StandardOutput.ReadToEnd();
Import DLL is fixed now, but another wild bug appeared named,
Fatal Python error: initfsencoding: unable to load the file system codec
ModuleNotFoundError: No module named 'encodings'
At this point I am lost and dont know what should I do next... any ideas are welcome, have a nice day.
UPDATE:
Deleted all other python interpretors aside from anaconda and one virtual env and tried following:
Run Python script from Visual Studio Code with given interpretor, works fine.
Run it from Anaconda prompt, aswell.
Added manually to system environment variables
PATH=D:\Programming\Python
PYTHONHOME=D:\Programming\Python
PYTHONPATH=D:\Programming\Python\Lib;D:\Programming\Python\DLLs;D:\Programming\Python\Lib\site-packages
So now I can successfully call "python" from cmd, like that and check version, the virtual env is python 3.6 and this is the right one.
Python is correct
But this is where all the fun begins you would expect "hello" in your console...
hell incarnate
Did not find correct answer to this problem, but discovered workaround in p2exe or pyinstaller.
Simply call pyinstaller.py --onefile xx.py and create exe file and pass that into process.
First of all I do not know if it is a bad practice to call python script from c# so if this is the case please tell me.My current problem is as follows.
MY c# code only runs the python script partially....
means (python script create only 4 files when it is supposed to create 10 files)
But When I run my script from cmd in windows I see complete functionality....
Another thing I saw is when I stop my Visual Studio(2013) I see the complete functionality
I am calling the python script(main.py) from c# like this...
public JsonResult FetchscrapyDataUrl(String website)
{
ProcessStartInfo start = new ProcessStartInfo();
start.FileName = #"C:\ProgramData\Anaconda3\python.exe";
start.Arguments = #"C:\Users\PycharmProjects\scraping_web\scrape_info\main.py";
//this is path to .py file from scrapy project
start.CreateNoWindow = false; // We don't need new window
start.UseShellExecute = false; // Do not use OS shell
//start.RedirectStandardOutput = true;// Any output, generated by application will be redirected back
start.RedirectStandardError = true; // Any error in standard output will be redirected back (for example exceptions)
Console.WriteLine("Python Starting");
start.RedirectStandardOutput = true;
using (Process process = Process.Start(start))
{
using (StreamReader reader = process.StandardOutput)
{
string stderr = process.StandardError.ReadToEnd(); // Here are the exceptions from our Python script
string result = reader.ReadToEnd(); // Here is the result of StdOut(for example: print "test")
Console.Write(result);
}
}
}
Why I am getting complete script functionality when I stop in Visual Studio(2013)??
I dont understand you motivation behind this. But why dont you use IronPython which is excellent addition to the .NET Framework, providing Python developers with the power of the .NET framework.
I want to convert a pdf file into an html file, so that I can extract the values in a table.
pdftohtml.exe can do this.
If I call the following on a command prompt I get an html page with the content from the pdf file:
pdftohtml.exe test.pdf test.html
This works as expected. Now I want to invoke this exe via C#.
I did the following:
string filename = #"C:\Temp\pdftohtml.exe";
Process proc = Process.Start(filename, "test.pdf test.html");
Unfortunately this does not work. I suspect that somehow the parameters are not past to the exe correctly.
When I call this exe via the command line with -c before the parameters I get an error:
pdftohtml.exe -c test.pdf test.html
leads to an error (rangecheck in .putdeviceprops).
Does someone know how to correctly invoke this program?
You can use the following stuff,
using System.Diagnostics;
// Prepare the process to run
ProcessStartInfo start = new ProcessStartInfo();
// Enter in the command line arguments, everything you would enter after the executable name itself
start.Arguments = arguments;
// Enter the executable to run, including the complete path
start.FileName = ExeName;
// Do you want to show a console window?
start.WindowStyle = ProcessWindowStyle.Hidden;
start.CreateNoWindow = true;
// Run the external process & wait for it to finish
using (Process proc = Process.Start(start))
{
proc.WaitForExit();
// Retrieve the app's exit code
exitCode = proc.ExitCode;
}
Usually /C will be used to execute the command and then terminate. In the above code, do modifications as required.
Is it possible to open a file with the default program without invoking the command line? I want to run a unit test and have the unit test open the file (PDF) at completion for visual inspection.
Just call Process.Start(filePath).
This will open the file in the user's default program.
I think this should work:
System.Diagnostics.Process.Start(#"c:\file.pdf"); //i.e provide the full path!
Simply use the following syntax:
System.Diagnostics.Process.Start(#"c:\yourfile.txt");
Process process = new System.Diagnostics.Process();
process.EnableRaisingEvents = false;
process.StartInfo.CreateNoWindow = true;
process.StartInfo.FileName = filePath;
string arguments = fileArguments;
process.StartInfo.Arguments = fileArguments;
process.Start();
process.WaitForExit();
This way you can invoke and put the file name in the pdf with parameters/arguments. You can also specify different programs and put it in the path, then the pdf name in the fileArguments. It's up to you.
if you use this code:
System.Diagnostics.Process.Start( "C:\...\...\myfile.pdf" );
the pdf should get opened by the default program associated to the .pdf extension.
is this what you wanted? I would be careful in putting this inside the unit test in case you include those tests in an automated build on the server, which runs with no logged in user, this could be an issue if it fails and if it does not fail, who is there to close Acrobat Reader? :D
I am trying to execute a OS command through C#. I have the following code taken from this webpage:
//Execute command on file
ProcessStartInfo procStart =
new ProcessStartInfo(#"C:\Users\Me\Desktop\Test\System_Instructions.txt",
"mkdir testDir");
//Redirects output
procStart.RedirectStandardOutput = true;
procStart.UseShellExecute = false;
//No black window
procStart.CreateNoWindow = true;
//Creates a process
System.Diagnostics.Process proc = new System.Diagnostics.Process();
//Set start info
proc.StartInfo = procStart;
//Start
proc.Start();
but when I attempt to run the code I get the following error:
{"The specified executable is not a valid application for this OS platform."}
What am I doing wrong? I have tried this example as well but got the same issue.
The overload of the ProcessStartInfo constructor you are using expects an executable file name and parameters to pass to it - a .txt file is not executable by itself.
It sounds more like you want to execute a batch file with commands within the file. For that check this SO thread: How do I use ProcessStartInfo to run a batch file?
Try setting the USESHELLEXECUTE member to TRUE instead of FALSE.
It worked for me - but I think this has reprocussions for certain users after publishing.
You are trying to execute a TXT file. That's why you get
{"The specified executable is not a valid application for this OS platform."}
Because, well, the specified executable (TXT) is not a valid application for this OS platform.
You would target an executable or other file that has a specified opening application. You're targeting a text file; what you should do is target Notepad, and then supply the path to your text file as an argument:
ProcessStartInfo info = new ProcessStartInfo
{
FileName = "C:\\Windows\System32\\notepad.exe",
Arguments = "C:\\Users\\Me\\Desktop\\Test\\System_Instructions.txt"
}
new Process.Start(info);
Alternatively, if you mean for your text file to be executed, it needs to be made a .bat file.
You are trying to execute this:
C:\Users\Me\Desktop\Test\System_Instructions.txt mkdir testDir
The shell has no clue how to "execute" a text file so the command fails.
If you want to execute this text file as a batch file, change file extension to .bat so the system understands it's a batch file, and then set UseShellExecute so it does the default action for it (= runs it, in case of a batch file).
If you want to open up the file in Notepad, use:
ProcessStartInfo procStart =
new ProcessStartInfo("notepad.exe", #"C:\Users\Me\Desktop\Test\System_Instructions.txt");
If you want to write into the file :
//In case the directory doesn't exist
Directory.CreateDirectory(#"C:\Users\Me\Desktop\Test\);
using (var file = File.CreateText(#"C:\Users\Me\Desktop\Test\System_Instructions.txt"))
{
file.WriteLine("mkdir testDir");
}
If you have commands in the text file that you want to execute, just rename it to .bat and it should work (and presumably the contents do something with "mkdir testDir" as a parameter?)
What are you trying to accomplish?
Create a directory? Use the "System.IO.Directory.CreateDirectory" method.
Open a .txt file with associated program? Use ProcessStartInfo(#".\filename.txt") with UseShellExecute set to true. This will cause the associated program for that file type to be executed, which might not be notepad.txt.