update modify parameter python script to accept changing pft names

parameter_files/fates_params_default.cdl

@@ -951,8 +951,8 @@ data:
   "broadleaf_evergreen_extratrop_shrub        ",
   "broadleaf_hydrodecid_extratrop_shrub       ",
   "broadleaf_colddecid_extratrop_shrub       ",
-  "broadleaf_evergreen_extratrop_shrub        ",
-  "broadleaf_colddecid_extratrop_shrub       ",
+  " broadleaf_evergreen_arctic_shrub                           ",
+  " broadleaf_colddecid_arctic_shrub                           ",
   "arctic_c3_grass                            ",
   "cool_c3_grass                              ",
   "c4_grass                                   " ;

tools/modify_fates_paramfile.py

@@ -73,22 +73,29 @@ def main():
         outputval = np.fromstring(args.val, sep=',', dtype=np.float64)
 
     else:
-
-        try:
-            outputval = np.float64(args.val)
-            if args.changeshape:
-                raise Exception
-        except:
+
+        # First check to see if we are modifying the pftname
+        if args.varname == 'fates_pftname':
+            rename_pft = True
+        else:
             try:
-                print('output variable not interpretable as real. trying array')
-                outputval = np.fromstring(args.val, sep=',', dtype=np.float64)
-                if len(outputval) == 0:
-                    raise RuntimeError('output variable needs to have size greater than zero')
+                outputval = np.float64(args.val)
+                if args.changeshape:
+                    raise Exception
             except:
-                if args.varname != 'fates_pftname':
-                    raise RuntimeError('output variable not interpretable as real or array')
-                else:
-                    rename_pft = True
+                try:
+                    print('output variable not interpretable as real. trying array')
+                    outputval = np.fromstring(args.val, sep=',', dtype=np.float64)
+                    # Note that fromstring does not yet raise a ValueError for fates_pftname
+                    # argument values.  As such, the exception below will not trigger.
+                    # Numpy warns that this will be a ValueError exception in a future update.
+                    if len(outputval) == 0:
+                        raise RuntimeError('output variable needs to have size greater than zero')
+                except:
+                    if args.varname != 'fates_pftname':
+                        raise RuntimeError('output variable not interpretable as real or array')
+                    else:
+                        rename_pft = True
     #
     #
     try: