make block writing a bit more readable.

pykat/finesse.py

@@ -393,14 +393,14 @@ class kat(object):
                     if values[1] == "FTblock":
                         newTag = values[2]
                         
-                        if self.__currentTag != None and newTag != self.__currentTag: 
+                        if self.__currentTag != None and self.__currentTag != NO_BLOCK: 
                             warnings.warn("found block {0} before block {1} ended".format(newTag, self.__currentTag))    
                             
                         if newTag in self.__blocks:
                             raise pkex.BasePyKatException("Block `{0}` has already been read".format(newTag))
                             
                         self.__blocks[newTag] = Block(newTag) # create new list to store all references to components in block
-                        self.__currentTag = newTag                            
+                        self.__currentTag = newTag
                         
                     if values[1] == "FTend":
                         self.__currentTag = NO_BLOCK
@@ -524,7 +524,7 @@ class kat(object):
                     raise pkex.BasePyKatException("pdtype command `{0}` is incorrect.".format(line))
                     
         self.__currentTag = NO_BLOCK 
-
+        
     def saveScript(self, filename=None):
         """
         Saves the current kat object to a Finesse input file
@@ -812,11 +812,12 @@ class kat(object):
         import datetime
         strtoday = datetime.datetime.now()
         out.append(strtoday.strftime("%% Generated by PyKat %d.%m.%Y %H:%M:%S\n") )
-        
+
         for key in self.__blocks:
             objs = self.__blocks[key].contents
 
-            if key != NO_BLOCK:
+            out.append("\n")
+            if key != NO_BLOCK and np.size(objs)>0:
                 out.append("%%% FTblock " + key + "\n")
             
             for obj in objs:
@@ -833,7 +834,7 @@ class kat(object):
                         else:
                             out.append(txt + "\n")
 
-            if key != NO_BLOCK:
+            if key != NO_BLOCK and np.size(objs)>0:
                 out.append("%%% FTend " + key + "\n")
             
         # now loop through all the nodes and get any gauss commands