important change to regrank interface, need some more test

python/xgboost.py

@@ -2,7 +2,7 @@
 import ctypes 
 
 # load in xgboost library
-#xglib = ctypes.cdll.LoadLibrary('./libxgboostpy.so')
+xglib = ctypes.cdll.LoadLibrary('./libxgboostpy.so')
 
 # entry type of sparse matrix
 class REntry(ctypes.Structure):
@@ -10,6 +10,13 @@ class REntry(ctypes.Structure):
 
 
 class DMatrix:
-    def __init__(fname = None):
-        self.__handle = xglib.
-    
+    def __init__(self,fname = None):
+        self.__handle = xglib.XGDMatrixCreate();
+        if fname != None:
+            xglib.XGDMatrixLoad(self.__handle, ctypes.c_char_p(fname), 0)
+    def __del__(self):
+        xglib.XGDMatrixFree(self.__handle)
+
+dmata = DMatrix('xx.buffer')
+
+