python返回行上的语法无效

Question

我在此代码返回时得到的语法无效：

def readDataSet(filename):

    fr = open(filename)                 

    numberOfLines = len(fr.readlines()) 

    returnMat = numpy.zeros((numberOfLines-1,3)) 

    classLabelVector = [] 
    classColorVector = [] 


    fr = open(filename) 
    index = 0

    for line in fr.readlines():  
        if index != 0:           
            line = line.strip()
            listFromLine = line.split('\t') 

            returnMat[index-1,:] = listFromLine[1:4] 

            classLabel = listFromLine[4]  

            if classLabel == "Buero":
                color = 'yellow'
            elif classLabel == "Wohnung":
                color = 'red'
            else:
                color = 'blue'

            classLabelVector.append(classLabel) 
            classColorVector.append(color)       

        index += 1


return returnMat,classLabelVector, classColorVector

它表示返回语法错误，但我不知道错误的位置。