almost final

build.py

 # coding=UTF-8
-from __future__ import print_function
-import json, sys
-import os.path
+import json, os.path
 
 def readin(path, func=lambda x: x.decode('utf8'), orelse=None):  # read bytes from path and treat it with func. If path does not exist, return orelse
     if os.path.exists(path):
@@ -22,7 +20,7 @@ if __name__ == '__main__':
         data = readin(src_json, json.loads, [{}])           # Load data
         lab = header+readin(src_md)+footer                  # Load text
 
-        # Swap placholders
+        # Swap placholders and write out each version for this class
         for ex_no, d in enumerate(data, start=1):
             d.update({'lp': unicode(ex_no), 'labno': unicode(i)})