diff --git a/examples/convert_xgboost.py b/examples/convert_xgboost.py
index caa21bb..7d39b50 100644
--- a/examples/convert_xgboost.py
+++ b/examples/convert_xgboost.py
@@ -1,17 +1,14 @@
 """
 Before use this file, install xgboost first
-""" 
-from __future__ import print_function
-import sys
-import xgboost as xgb
+"""
 import os
 import struct
-from ctypes import cdll
-from ctypes import c_float, c_uint, c_char_p, c_bool
+import sys
+
+import xgboost as xgb
 
-LIB_PATH = "./libgbdt.so"
 
-def convert(input_model, objective, output_file):
+def convert(input_model, output_file):
     model = xgb.Booster()
     model.load_model(input_model)
     tmp_file = output_file + ".gbdt_rs.mid"
@@ -27,11 +24,11 @@ def convert(input_model, objective, output_file):
             base_score = struct.unpack('f',f.read(4))[0]
     except Exception as e:
         print("error: ", e)
-        return 1
+        return
     
     if os.path.exists(tmp_file):
         print("Intermediate file %s exists. Please remove this file or change your output file path" % tmp_file)
-        return 1
+        return
 
     # dump json
     model.dump_model(tmp_file, dump_format="json")
@@ -46,19 +43,16 @@ def convert(input_model, objective, output_file):
     except Exception as e:
         print("error: ", e)
         os.remove(tmp_file)
-        return 1
+        return
 
     os.remove(tmp_file)
-    return 0
 
 
 if __name__ == "__main__":
-    if len(sys.argv) != 4:
-        print("usage: python script input_model_path objective output_file_path")
-        print("supported booster: gbtree")
-        print("supported objective: 'reg:linear', 'binary:logistic', 'reg:logistic'," + \
-        "'binary:logitraw', 'multi:softmax', 'multi:softprob', 'rank:pairwise'")
+    if len(sys.argv) != 3:
+        print("usage: python convert_xgboost.py <input_xgboost_model_path> <output_gbdt_model_path>")
+        print("--supported booster: gbtree")
+        print("--supported objective: 'reg:linear', 'binary:logistic', 'reg:logistic', "
+              "'binary:logitraw', 'multi:softmax', 'multi:softprob', 'rank:pairwise'")
         exit(1)
-    convert(sys.argv[1], sys.argv[2], sys.argv[3])
-    
-
+    convert(sys.argv[1], sys.argv[2])