Buildings.Utilities.IO.Python27.Functions

Information

This package contains functions that call Python.

Package Content

Name	Description
exchange	Function that communicates with Python
Examples	Collection of models that illustrate model use and test models
BaseClasses	Package with functions that call Python

Buildings.Utilities.IO.Python27.Functions.exchange

Information

This function is a wrapper for Buildings.Utilities.IO.Python27.Functions.BaseClasses.exchange. It adds the directory modelica://Buildings/Resources/Python-Sources to the environment variable PYTHONPATH prior to calling the function that exchanges data with Python. After the function call, the PYTHONPATH is set back to what it used to be when entering this function. See Buildings.Utilities.IO.Python27.UsersGuide for instructions, and Buildings.Utilities.IO.Python27.Functions.Examples for examples.

Inputs

Type	Name	Default	Description
String	moduleName		Name of the python module that contains the function
String	functionName	moduleName	Name of the python function
Real	dblWri[max(1, nDblWri)]		Double values to write
Integer	intWri[max(1, nIntWri)]		Integer values to write
String	strWri[max(1, nStrWri)]		String values to write
Integer	nDblWri		Number of double values to write
Integer	nDblRea		Number of double values to read
Integer	nIntWri		Number of integer values to write
Integer	nIntRea		Number of integer values to read
Integer	nStrWri		Number of strings to write

Outputs

Type	Name	Description
Real	dblRea[max(1, nDblRea)]	Double values returned by Python
Integer	intRea[max(1, nIntRea)]	Integer values returned by Python

Modelica definition

function exchange "Function that communicates with Python"
  input String moduleName 
    "Name of the python module that contains the function";
  input String functionName=moduleName "Name of the python function";

  input Real    dblWri[max(1, nDblWri)] "Double values to write";
  input Integer intWri[max(1, nIntWri)] "Integer values to write";
  input String  strWri[max(1, nStrWri)] "String values to write";

  input Integer nDblWri(min=0) "Number of double values to write";
  input Integer nDblRea(min=0) "Number of double values to read";

  input Integer nIntWri(min=0) "Number of integer values to write";
  input Integer nIntRea(min=0) "Number of integer values to read";

  input Integer nStrWri(min=0) "Number of strings to write";
//  input Integer nStrRea(min=0) "Number of strings to read";
//  input Integer strLenRea(min=0)
//    "Maximum length of each string that is read. If exceeded, the simulation stops with an error";

  output Real    dblRea[max(1, nDblRea)] "Double values returned by Python";
  output Integer intRea[max(1, nIntRea)] "Integer values returned by Python";
protected 
  String pytPat "Value of PYTHONPATH environment variable";
  String pytPatBuildings "PYTHONPATH of Buildings library";
  Boolean havePytPat "true if PYTHONPATH is already set by the user";
//--  String filNam = "file://Utilities/IO/Python27/UsersGuide/package.mo"
//--    "Name to a file of the Buildings library";
algorithm 
 // Get the directory to Buildings/Resources/Python-Sources
//-- The lines below do not work in Dymola 2014 due to an issue with the loadResource
//-- (ticket #15168). This will be fixed in future versions.
//-- pytPatBuildings := Buildings.BoundaryConditions.WeatherData.BaseClasses.getAbsolutePath(uri=filNam);
//-- pytPatBuildings := Modelica.Utilities.Strings.replace(
//--   string=pytPatBuildings,
//--   searchString=filNam,
//--   replaceString="Resources/Python-Sources");
 // The next line is a temporary fix for the above problem
 pytPatBuildings := "Resources/Python-Sources";
 // Update the PYTHONPATH variable
 (pytPat, havePytPat) :=Modelica.Utilities.System.getEnvironmentVariable("PYTHONPATH");
 if havePytPat then
   Modelica.Utilities.System.setEnvironmentVariable(name="PYTHONPATH",
      content=pytPat + ":" + pytPatBuildings);
 else
   Modelica.Utilities.System.setEnvironmentVariable(name="PYTHONPATH",
      content=pytPatBuildings);
 end if;
 // Call the exchange function
 (dblRea, intRea) :=BaseClasses.exchange(
    moduleName=moduleName,
    functionName=functionName,
    dblWri=dblWri,
    intWri=intWri,
    strWri=strWri,
    nDblWri=nDblWri,
    nDblRea=nDblRea,
    nIntWri=nIntWri,
    nIntRea=nIntRea,
    nStrWri=nStrWri);

 // Change the PYTHONPATH back to what it was so that the function has no
 // side effects.
 if havePytPat then
   Modelica.Utilities.System.setEnvironmentVariable(name="PYTHONPATH",
      content=pytPat);
 else
   Modelica.Utilities.System.setEnvironmentVariable(name="PYTHONPATH",
      content="");
 end if;

end exchange;