Add new oddie submodule

Author: PMeira

dss_python_backend/__init__.py

@@ -15,18 +15,14 @@
 
 if os.environ.get('DSS_EXTENSIONS_DEBUG', '') != '1':
     altdss_lib_path = altdss_lib_parent_path.joinpath('libaltdss_capi.so')
-    pass
 else:
     import warnings
     warnings.warn('Environment variable DSS_EXTENSIONS_DEBUG=1 is set: loading the debug version of the DSS C-API library')
     altdss_lib_path = altdss_lib_parent_path.joinpath('libaltdss_capid.so')
-    pass
-
 
 if not altdss_lib_path.exists():
     raise RuntimeError('AltDSS library not found!')
 
-
 # Basic initialization -- load the library and prepare the structures
 lib = _altdss_capi_loader.ffi.new('AltDSSCAPI*')
 
@@ -44,7 +40,7 @@
 if _init_result != 1:
     raise RuntimeError(f'AltDSS library found but could not be loaded (code {_init_result})!')
 
-# Ensure this is called at least once. This was moved from 
+# For AltDSS, ensure this is called at least once. This was moved from 
 # CffiApiUtil so we call it as soon as the DLL/so is loaded.
 lib.DSS_Start(ffi.NULL, 0)
 

dss_python_backend/oddie.py

@@ -0,0 +1,42 @@
+'''
+This file provides access to the Oddie library.
+Note that it does not initialize the OpenDSS or OpenDSS-C libraries, that is a 
+second step. The same Oddie instance can be used to load multiple engine libraries.
+'''
+import os
+from . import _altdss_capi_loader
+from ._altdss_capi_loader import ffi, lib as loader_lib
+from pathlib import Path
+
+altdss_lib_parent_path = Path(_altdss_capi_loader.__file__).absolute().parent
+
+if os.environ.get('DSS_EXTENSIONS_DEBUG', '') != '1':
+    oddie_lib_path = altdss_lib_parent_path.joinpath('libaltdss_oddie_capi.so')
+else:
+    import warnings
+    warnings.warn('Environment variable DSS_EXTENSIONS_DEBUG=1 is set: loading the debug version of the AltDSS Oddie library')
+    oddie_lib_path = altdss_lib_parent_path.joinpath('libaltdss_oddie_capid.so')
+
+if not oddie_lib_path.exists():
+    print(oddie_lib_path)
+    raise RuntimeError('Oddie library not found!')
+
+# Basic initialization -- load the library and prepare the structures
+lib = _altdss_capi_loader.ffi.new('AltDSSCAPI*')
+
+_init_result = loader_lib.AltDSSCAPILibInit(
+    str(oddie_lib_path).encode(),
+    ffi.NULL,
+    b"AltDSSOddieCAPIInit",
+    lib,
+    ffi.sizeof(lib[0]), 
+    0,
+    0,
+    ffi.NULL
+)
+
+if _init_result != 1:
+    raise RuntimeError(f'Oddie library found but could not be loaded (code {_init_result})!')
+
+# Compared to the main "lib" in __init__.py, we will not call DSS_Start yet
+# since the actual engine is not loaded.