'builtin_function_or_method'对象不可迭代？

Question

运行以下代码时出现此错误：

  

'builtin_function_or_method'对象不可迭代

我搜索过stackoverflow，但无法找到我的问题的答案......请帮助我！

def file2matrix(filename):
    fr = open(filename)
    arrayOLines = fr.readlines()
    numberOfLines = len(arrayOLines)
    returnMat = zeros((numberOfLines, 3))
    classLabelVector = []
    index = 0
    for line in arrayOLines:
        line = line.strip()
        listFromLine = line.split('\t')
        returnMat[index, :] = listFromLine[0:3]
        classLabelVector.append(int(listFromLine[-1]))
        index += 1
    return returnMat, classLabelVector

这是结果......

>>> datingDataMat,datingLabels = kNN.file2matrix("datingTestSet.txt")
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "C:\Users\Dennis Yang\PycharmProjects\mlaction\kNN.py", line 28, in file2matrix
    for line in arrayOLines:
TypeError: 'builtin_function_or_method' object is not iterable