Is there a guide on how to configure DWSIM and Python installs to work togeather?

[Mark Burgoyne]

I'm having the similar issues as reported in this post , with errors using Automation2() and then it telling me that it could not load System.Windows.Forms when I tried Automation3()

I am frankly not sure if I should be using Python, or IronPython, whether the version of Python matters, or whether there are other libraries / frameworks I should have also installed

It would be really helpful for me if someone could outline how someone starting from a fresh system (no DWSIM, no Python, no NET frameworks etc) needs to set things up to get this working

BTW - I'm on a Win11 system, and the error message(s) I have been getting are when trying to run the below starter script;

Thanks in advance

Mark

from pythonnet import load
load("coreclr")

import clr

# Load the DWSIM automation assembly
clr.AddReference('DWSIM.Automation')

dwsimpath = "C:\\Path\\to\\DWSIM\\"

clr.AddReference(dwsimpath + "CapeOpen.dll")
clr.AddReference(dwsimpath + "DWSIM.Automation.dll")
clr.AddReference(dwsimpath + "DWSIM.Interfaces.dll")
clr.AddReference(dwsimpath + "DWSIM.GlobalSettings.dll")
clr.AddReference(dwsimpath + "DWSIM.SharedClasses.dll")
clr.AddReference(dwsimpath + "DWSIM.Thermodynamics.dll")
clr.AddReference(dwsimpath + "DWSIM.Thermodynamics.ThermoC.dll")
clr.AddReference(dwsimpath + "DWSIM.UnitOperations.dll")
clr.AddReference(dwsimpath + "DWSIM.Inspector.dll")
clr.AddReference(dwsimpath + "System.Buffers.dll")

# Import the necessary namespaces from DWSIM
from DWSIM.Automation import Automation3
#from DWSIM.Automation import Automation2

def calculate_mixture_density(pressure, temperature, co2_fraction, h2s_fraction):
    # Initialize DWSIM Automation Interface
    interop = Automation3()
    #interop = Automation2()

    # Create a new material stream in DWSIM
    stream = interop.CreateMaterialStream()

    # Set the compounds to CO2 and H2S
    stream.SetCompound("CarbonDioxide")
    stream.SetCompound("HydrogenSulfide")

    # Define the molar fractions
    stream.SetMolarFraction("CarbonDioxide", co2_fraction)
    stream.SetMolarFraction("HydrogenSulfide", h2s_fraction)

    # Define the temperature (K) and pressure (Pa)
    stream.SetTemperature(temperature)
    stream.SetPressure(pressure)

    # Set the thermodynamic model to GERG2008 EOS
    stream.SetPropertyPackage("GERG2008")

    # Calculate properties
    interop.CalculateAllProperties(stream)

    # Get the density of the mixture
    density = stream.GetDensity()

    # Release the COM object
    stream.Release()

    return density

# Example usage
pressure = 5000000  # in Pascals (5 MPa)
temperature = 300  # in Kelvin
co2_fraction = 0.7  # 70% CO2
h2s_fraction = 0.3  # 30% H2S
density = calculate_mixture_density(pressure, temperature, co2_fraction, h2s_fraction)
print(f"Density of CO2 and H2S mixture at {pressure} Pa and {temperature} K is {density} kg/m³")

[Daniel Medeiros]

what are the error messages?

[Mark Burgoyne]

Thanks Daniel. When I use the Automation2(), I get the following;

NullReferenceException: Object reference not set to an instance of an object.
at DWSIM.Automation.Automation2..ctor() in C:\Users\Daniel\source\repos\DanWBR\dwsim\DWSIM.Automation\Automation.cs:line 135
at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
at System.Reflection.MethodBaseInvoker.InvokeConstructorWithoutAlloc(Object obj, Boolean wrapInTargetInvocationException)

And when I try the Automation3(), I get the following;

---

FileNotFoundException Traceback (most recent call last)
FileNotFoundException: Could not load file or assembly 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. The system cannot find the file specified.
File name: 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'
at DWSIM.FlowsheetBase.FlowsheetBase._Closure$__187-0._Lambda$__9()
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)

The above exception was the direct cause of the following exception:

AggregateException Traceback (most recent call last)
Cell In[4], line 66
64 co2_fraction = 0.7 # 70% CO2
65 h2s_fraction = 0.3 # 30% H2S
---> 66 density = calculate_mixture_density(pressure, temperature, co2_fraction, h2s_fraction)
67 print(f"Density of CO2 and H2S mixture at {pressure} Pa and {temperature} K is {density} kg/m³")

Cell In[4], line 30, in calculate_mixture_density(pressure, temperature, co2_fraction, h2s_fraction)
27 def calculate_mixture_density(pressure, temperature, co2_fraction, h2s_fraction):
28 # Initialize DWSIM Automation Interface
29 #interop = Automation2()
---> 30 interop = Automation3()
32 # Create a new material stream in DWSIM
33 stream = interop.CreateMaterialStream()

AggregateException: One or more errors occurred. (Could not load file or assembly 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. The system cannot find the file specified.) (Could not load file or assembly 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. The system cannot find the file specified.) (Could not load file or assembly 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. The system cannot find the file specified.)
---> System.IO.FileNotFoundException: Could not load file or assembly 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. The system cannot find the file specified.
File name: 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'
at DWSIM.FlowsheetBase.FlowsheetBase._Closure$__187-0._Lambda$__9()
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.WaitAllCore(Task[] tasks, Int32 millisecondsTimeout, CancellationToken cancellationToken)
at System.Threading.Tasks.Task.WaitAll(Task[] tasks)
at DWSIM.FlowsheetBase.FlowsheetBase.AddPropPacks() in C:\Users\Daniel\source\repos\DanWBR\dwsim\DWSIM.FlowsheetBase\FlowsheetBase.vb:line 3461
at DWSIM.Automation.Automation3..ctor() in C:\Users\Daniel\source\repos\DanWBR\dwsim\DWSIM.Automation\Automation.cs:line 244
at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
at System.Reflection.MethodBaseInvoker.InvokeConstructorWithoutAlloc(Object obj, Boolean wrapInTargetInvocationException)
---> (Inner Exception #1) System.IO.FileNotFoundException: Could not load file or assembly 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. The system cannot find the file specified.
File name: 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'
at DWSIM.FlowsheetBase.FlowsheetBase._Closure$__187-0._Lambda$__11()
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)<---

---> (Inner Exception #2) System.IO.FileNotFoundException: Could not load file or assembly 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. The system cannot find the file specified.
File name: 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'
at DWSIM.FlowsheetBase.FlowsheetBase._Closure$__187-0._Lambda$__12()
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)<---

[Daniel Medeiros]

try replacing

load("coreclr")

by

load("netfx")

[Mark Burgoyne]

Ok, after that I get a different error, and I also get the same missing attribute error when I try again with Automation2;

---

AttributeError Traceback (most recent call last)
Cell In[1], line 67
65 co2_fraction = 0.7 # 70% CO2
66 h2s_fraction = 0.3 # 30% H2S
---> 67 density = calculate_mixture_density(pressure, temperature, co2_fraction, h2s_fraction)
68 print(f"Density of CO2 and H2S mixture at {pressure} Pa and {temperature} K is {density} kg/m³")

Cell In[1], line 34, in calculate_mixture_density(pressure, temperature, co2_fraction, h2s_fraction)
31 interop = Automation3()
33 # Create a new material stream in DWSIM
---> 34 stream = interop.CreateMaterialStream()
36 # Set the compounds to CO2 and H2S
37 stream.SetCompound("CarbonDioxide")

AttributeError: 'Automation3' object has no attribute 'CreateMaterialStream'

[Daniel Medeiros]

try following this gist: https://gist.github.com/DanWBR/fe979513ba32627b47b02888061b69f4

[Mark Burgoyne]

That seemed to work just fine, including creating the flow diagram image