函数不返回任何python

Question

我对Python很陌生。我正在尝试编写一个函数来执行以下操作，并在以后的代码部分中重用该函数： （函数的作用）：

• 求两个列表元素之间的余弦值
• 将值添加到列表中并计算平均值
• 将平均值追加到列表中
• 返回方法列表

然后我想根据上面函数返回的列表进行计算。但是，函数（即knearest_similarity（tfidf_datamatrix））不返回任何内容。第二个函数（即threshold_function（））中的print命令不显示任何内容。有人能看看代码，告诉我我做错了什么吗。在

def knearest_similarity(tfidf_datamatrix):
    k_nearest_cosineMean = []
    for datavector in tfidf_datamatrix:
        cosineValueSet = []
        for trainingvector in tfidf_vectorizer_trainingset:
            cosineValue = cx(datavector, trainingvector)
            cosineValueSet.append(cosineValue)
        similarityMean_of_k_nearest_neighbours = np.mean(heapq.nlargest(k_nearest_neighbours, cosineValueSet))    #the cosine similarity score of top k nearest neighbours
        k_nearest_cosineMean.append(similarityMean_of_k_nearest_neighbours)        
    print k_nearest_cosineMean
    return k_nearest_cosineMean


def threshold_function():  
    mean_cosineScore_mean = np.mean(knearest_similarity(tfidf_matrix_testset))
    std_cosineScore_mean = np.std(knearest_similarity(tfidf_matrix_testset))
    threshold = mean_cosineScore_mean - (3*std_cosineScore_mean)
    print "The Mean of the mean of cosine similarity score for a normal Behaviour:", mean_cosineScore_mean #The mean will be used for finding the threshold
    print "The standard deviation of the mean of cosine similarity score:", std_cosineScore_mean  #The standstart deviation is also used to find threshold
    print "The threshold for normal behaviour should be (Mean - 3*standard deviation):", threshold
    return threshold

编辑

我尝试为要使用的函数定义两个全局变量（即tfidf_vectorizer_trainingset和tfidf_matrix_testset）。在

^{pr2}$

但是threshold_function（）中的打印命令显示如下：

 The Mean of the mean of cosine similarity score for a normal Behaviour: nan
The standard deviation of the mean of cosine similarity score: nan
The threshold for normal behaviour should be (Mean - 3*standard deviation): nan

编辑2 我发现最接近余弦平均值的第一个值是nan。删除值后，我设法得到了有效的计算。在

Answer 1

我threshold_function()的第一行称为knearest_similarity(tfidf_matrix_testset)，但是你从来没有定义{}是什么。你在第二行也这样做。在第三行中，您使用第二行的输出。给tfidf_matrix_testset一个值。在