diff --git a/examples/undocumented/python/preprocessor_logplusone.py b/examples/undocumented/python/preprocessor_logplusone.py
index 96b5e193f95..9d093871a8a 100644
--- a/examples/undocumented/python/preprocessor_logplusone.py
+++ b/examples/undocumented/python/preprocessor_logplusone.py
@@ -18,8 +18,8 @@ def preprocessor_logplusone (fm_train_real=traindat,fm_test_real=testdat,width=1
 
 	preproc = LogPlusOne()
 	preproc.fit(feats_train)
-        feats_train = preproc.apply(feats_train)
-        feats_test = preproc.apply(feats_test)
+	feats_train = preproc.apply(feats_train)
+	feats_test = preproc.apply(feats_test)
 
 	kernel=Chi2Kernel(feats_train, feats_train, width, size_cache)
 
diff --git a/examples/undocumented/python/preprocessor_normone.py b/examples/undocumented/python/preprocessor_normone.py
index 20f0276b95e..2a91db8bd1e 100644
--- a/examples/undocumented/python/preprocessor_normone.py
+++ b/examples/undocumented/python/preprocessor_normone.py
@@ -18,8 +18,8 @@ def preprocessor_normone (fm_train_real=traindat,fm_test_real=testdat,width=1.4,
 
 	preprocessor=NormOne()
 	preprocessor.fit(feats_train)
-        feats_train = preprocessor.apply(feats_train)
-        feats_test = preprocessor.apply(feats_test)
+	feats_train = preprocessor.apply(feats_train)
+	feats_test = preprocessor.apply(feats_test)
 
 	kernel=Chi2Kernel(feats_train, feats_train, width, size_cache)
 
diff --git a/examples/undocumented/python/preprocessor_prunevarsubmean.py b/examples/undocumented/python/preprocessor_prunevarsubmean.py
index 4f371cc4931..b14985fe0a9 100644
--- a/examples/undocumented/python/preprocessor_prunevarsubmean.py
+++ b/examples/undocumented/python/preprocessor_prunevarsubmean.py
@@ -17,8 +17,8 @@ def preprocessor_prunevarsubmean (fm_train_real=traindat,fm_test_real=testdat,wi
 
 	preproc=PruneVarSubMean()
 	preproc.fit(feats_train)
-        feats_train = preproc.apply(feats_train)
-        feats_test = preproc.apply(feats_test)
+	feats_train = preproc.apply(feats_train)
+	feats_test = preproc.apply(feats_test)
 
 	kernel=Chi2Kernel(feats_train, feats_train, width, size_cache)
 
diff --git a/examples/undocumented/python/preprocessor_randomfouriergausspreproc.py b/examples/undocumented/python/preprocessor_randomfouriergausspreproc.py
index d45bb9c4b8e..eddf328acfa 100644
--- a/examples/undocumented/python/preprocessor_randomfouriergausspreproc.py
+++ b/examples/undocumented/python/preprocessor_randomfouriergausspreproc.py
@@ -20,8 +20,8 @@ def preprocessor_randomfouriergausspreproc (fm_train_real=traindat,fm_test_real=
 
 	preproc=RandomFourierGaussPreproc()
 	preproc.fit(feats_train)
-        feats_train = preproc.apply(feats_train)
-        feats_test = preproc.apply(feats_test)
+	feats_train = preproc.apply(feats_train)
+	feats_test = preproc.apply(feats_test)
 
 	kernel=Chi2Kernel(feats_train, feats_train, width, size_cache)
 
diff --git a/examples/undocumented/python/preprocessor_sortulongstring.py b/examples/undocumented/python/preprocessor_sortulongstring.py
index df8d9d3dff8..9914b4d8181 100644
--- a/examples/undocumented/python/preprocessor_sortulongstring.py
+++ b/examples/undocumented/python/preprocessor_sortulongstring.py
@@ -26,8 +26,8 @@ def preprocessor_sortulongstring (fm_train_dna=traindna,fm_test_dna=testdna,orde
 
 	preproc = SortUlongString()
 	preproc.fit(feats_train)
-        feats_train = preproc.apply(feats_train)
-        feats_test = preproc.apply(feats_test)
+	feats_train = preproc.apply(feats_train)
+	feats_test = preproc.apply(feats_test)
 
 	kernel=CommUlongStringKernel(feats_train, feats_train, use_sign)
 
diff --git a/examples/undocumented/python/preprocessor_sortwordstring.py b/examples/undocumented/python/preprocessor_sortwordstring.py
index ab6d1e1fb5e..0a51f04d50f 100644
--- a/examples/undocumented/python/preprocessor_sortwordstring.py
+++ b/examples/undocumented/python/preprocessor_sortwordstring.py
@@ -23,7 +23,7 @@ def preprocessor_sortwordstring (fm_train_dna=traindna,fm_test_dna=testdna,order
 	charfeat=StringCharFeatures(fm_test_dna, DNA)
 	feats_test=StringWordFeatures(charfeat.get_alphabet())
 	feats_test.obtain_from_char(charfeat, order-1, order, gap, reverse)
-        feats_test = preproc.apply(feats_test)
+	feats_test = preproc.apply(feats_test)
 
 	kernel=CommWordStringKernel(feats_train, feats_train, use_sign)