Convert main modulef90 to python

CMakeLists.txt

@@ -100,7 +100,6 @@ LIST(APPEND PROCESS_SRCS
     structure_variables.f90
     output.f90
     init_module.f90
-    main_module.f90
     error_handling.f90
     global_variables.f90
     constraint_variables.f90
@@ -118,6 +117,7 @@ LIST(APPEND PROCESS_SRCS
     stellarator_variables.f90
     stellarator.f90
     stellarator_configuration.f90
+    input.f90
 )
 
 PREPROCESS()

process/exceptions.py

@@ -0,0 +1,29 @@
+class ProcessException(Exception):
+    """A base Exception to derive other PROCESS exceptions from"""
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args)
+        self._diagnostics = kwargs
+
+    def __str__(self):
+        exception_message = super().__str__()
+        diagnostics_message = "\n".join(
+            [f"\t{d}: {repr(v)}" for d, v in self._diagnostics.items()]
+        )
+
+        if diagnostics_message:
+            return f"{exception_message}\n{diagnostics_message}"
+
+        return exception_message
+
+
+class ProcessValidationError(ProcessException):
+    """Exception raised when validating PROCESS input.
+
+    E.g. initial values, constraint/variable combinations, switch combinations"""
+
+    pass
+
+
+class ProcessValueError(ProcessException, ValueError):
+    pass