diff --git a/infiniteworld.py b/infiniteworld.py
index c541258..a81b867 100644
--- a/infiniteworld.py
+++ b/infiniteworld.py
@@ -37,12 +37,6 @@ Player = 'Player'
 
 __all__ = ["ZeroChunk", "InfdevChunk", "MCInfdevOldLevel", "MCAlphaDimension", "ZipSchematic"]
 
-def exhaust(_iter):
-    i = 0
-    for i in _iter:
-        pass
-    return i
-
 import re
 
 convert = lambda text: int(text) if text.isdigit() else text
@@ -1647,7 +1641,7 @@ class MCInfdevOldLevel(EntityLevel):
         self.loadedChunkQueue.discard(chunk)
 
     def chunkDidLoad(self, chunk):
-        if not chunk in self.loadedChunkQueue:
+        if chunk not in self.loadedChunkQueue:
             self.loadedChunkQueue.append(chunk);
             if self.loadedChunkLimit and (len(self.loadedChunkQueue) > self.loadedChunkLimit):
                 oldestChunk = self.loadedChunkQueue[0];
@@ -2003,8 +1997,7 @@ class MCInfdevOldLevel(EntityLevel):
         info(u"Saved {0} chunks".format(dirtyChunkCount))
 
     def generateLights(self, dirtyChunks=None):
-        for i in self.generateLightsIter(dirtyChunks):
-            pass
+        return exhaust(self.generateLightsIter(dirtyChunks))
 
     def generateLightsIter(self, dirtyChunks=None):
         """ dirtyChunks may be an iterable yielding (xPos,zPos) tuples
@@ -2570,8 +2563,7 @@ class MCInfdevOldLevel(EntityLevel):
 
 
     def copyBlocksFrom(self, sourceLevel, sourceBox, destinationPoint, blocksToCopy=None, entities=True):
-        for i in self.copyBlocksFromIter(sourceLevel, sourceBox, destinationPoint, blocksToCopy, entities):
-            pass
+        return exhaust(self.copyBlocksFromIter(sourceLevel, sourceBox, destinationPoint, blocksToCopy, entities))
 
     def copyBlocksFromIter(self, sourceLevel, sourceBox, destinationPoint, blocksToCopy=None, entities=True):
         (x, y, z) = destinationPoint;
diff --git a/level.py b/level.py
index 0ac3212..3ed2bcf 100644
--- a/level.py
+++ b/level.py
@@ -476,8 +476,7 @@ class MCLevel(object):
 
 
     def copyBlocksFrom(self, sourceLevel, sourceBox, destinationPoint, blocksToCopy=None, entities=True):
-        for i in self.copyBlocksFromIter(sourceLevel, sourceBox, destinationPoint, blocksToCopy, entities):
-            pass
+        return exhaust(self.copyBlocksFromIter(sourceLevel, sourceBox, destinationPoint, blocksToCopy, entities))
 
     def copyBlocksFromIter(self, sourceLevel, sourceBox, destinationPoint, blocksToCopy=None, entities=True):
         if (not sourceLevel.isInfinite) and not(
diff --git a/mclevelbase.py b/mclevelbase.py
index 78f6c46..1936cb0 100644
--- a/mclevelbase.py
+++ b/mclevelbase.py
@@ -63,4 +63,14 @@ class ChunkNotPresent(Exception): pass
 class RegionMalformed(Exception): pass
 class ChunkMalformed(ChunkNotPresent): pass
 
+
+def exhaust(_iter):
+    """Functions named ending in "Iter" return an iterable object that does
+    long-running work and yields progress information on each call. exhaust()
+    is used to implement the non-Iter equivalents"""
+    i = None
+    for i in _iter:
+        pass
+    return i
+
 from level import MCLevel, EntityLevel
diff --git a/schematic.py b/schematic.py
index 7b7bd7f..37e4ace 100644
--- a/schematic.py
+++ b/schematic.py
@@ -473,10 +473,7 @@ def adjustExtractionParameters(self, box):
     return box, (destX, destY, destZ)
 
 def extractSchematicFrom(sourceLevel, box, entities=True):
-    i = None
-    for i in extractSchematicFromIter(sourceLevel, box, entities):
-        pass
-    return i
+    return exhaust(extractSchematicFromIter(sourceLevel, box, entities))
 
 def extractSchematicFromIter(sourceLevel, box, entities=True):
     p = sourceLevel.adjustExtractionParameters(box);
@@ -496,9 +493,7 @@ MCLevel.adjustExtractionParameters = adjustExtractionParameters
 
 import tempfile
 def extractZipSchematicFrom(sourceLevel, box, zipfilename=None, entities=True):
-    for i in extractZipSchematicFromIter(sourceLevel, box, zipfilename, entities):
-        pass
-    return i
+    return exhaust(extractZipSchematicFromIter(sourceLevel, box, zipfilename, entities))
 
 def extractZipSchematicFromIter(sourceLevel, box, zipfilename=None, entities=True):
     #converts classic blocks to alpha