diff --git a/function.py b/function.py
index 4ccf4e8..22374b0 100644
--- a/function.py
+++ b/function.py
@@ -54,7 +54,7 @@ def normalize(dataSet):
     return normDataSet, ranges, minVals
 
 
-def classify0(inX, dataSet, labels, k):
+def classify0(inX, dataSet, labels, k=20):
     """
     KNN 分类算法。