Group CLI demo into subdirectory. (#6258)

CLI is not most developed interface. Putting them into correct directory can help new users to avoid it as most of the use cases are from a language binding.

demo/CLI/binary_classification/mknfold.py

@@ -0,0 +1,29 @@
+#!/usr/bin/python
+import sys
+import random
+
+if len(sys.argv) < 2:
+    print ('Usage:<filename> <k> [nfold = 5]')
+    exit(0)
+
+random.seed( 10 )
+
+k = int( sys.argv[2] )
+if len(sys.argv) > 3:
+    nfold = int( sys.argv[3] )
+else:
+    nfold = 5
+
+fi = open( sys.argv[1], 'r' )
+ftr = open( sys.argv[1]+'.train', 'w' )
+fte = open( sys.argv[1]+'.test', 'w' )
+for l in fi:
+    if random.randint( 1 , nfold ) == k:
+        fte.write( l )
+    else:
+        ftr.write( l )
+
+fi.close()
+ftr.close()
+fte.close()
+