summer update

uniquelist.py

@@ -1,20 +1,32 @@
+# move it to utils.py
+# also look at frozensets
+# look at import collections - lot of good data structures
+# learn about co-routines (returning generators from generators i.e. yield
+# statement)
+
+
 class uniquelist(list):
+
     ''' A list whose every value is unique.
     uniquelist.append(val) or __setitem__(pos,val) i.e. uniquelist[pos]=val is ignored if val is already in uniquelist.
     Returns True if the value is added, else returns False. '''
-    def __setitem__(self,pos,val):
+
+    def __setitem__(self, pos, val):
         if val not in self:
-            super(uniquelist,self).__setitem__(pos,val)
+            super(uniquelist, self).__setitem__(pos, val)
             return True
         else:
             return False
-    def append(self,val):
+
+    def append(self, val):
         if val not in self:
-            super(uniquelist,self).append(val)
+            super(uniquelist, self).append(val)
             return True
         else:
             return False
-    def extend(self,iterable):
-        for temp in iterable: # todo: use yield so that it is not copied into memory
+
+    def extend(self, iterable):
+        # todo: use yield so that it is not copied into memory
+        for temp in iterable:
             self.append(temp)
-    # Todo: Allow for type checking by allowing a type_of_members to be set
+    # Todo: Allow for type checking by allowing a type_of_members to be set