RandSelectNegativeSample() --> RandSelectNegativeSamples()

The function is defined as singular on line 5 but it returns multiple samples and is called a plural on line 23.  This PR suggest using the plural form in both places.  Discovered using the tests that were suppressed in apachecn@4e129cd#commitcomment-33663962

Author: cclauss

src/py3.x/16.RecommenderSystems/test_lfm.py

@@ -2,7 +2,7 @@
 
 
 # 负样本采样过程
-def RandomSelectNegativeSample(self, items):
+def RandSelectNegativeSamples(self, items):
     ret = {key: 1 for key in items}
     n = 0
     for i in range(0, len(items) * 3):