TypeError: 'float' object has no attribute '__getitem__'

Question

This code is a beginning attempt at reading a csv file into a couple of lists. I'm getting the error below, and I can't see why the float isn't being returned. Thanks for your help!

 File "main.py", line 32, in <module>
     LR.openfile('djia_temp.csv')  
 File "main.py", line 9, in openfile
     self.xs = self.tempDiff(dataAvgandtemp)   
 File "main.py", line 18, in tempDiff
     tdArray.append([vector[0]-vector[1]]) 
 TypeError: 'float' object has no attribute '__getitem__'

Code:

from processFile import processFile
import numpy as np

class processFile:

    @staticmethod
    def wholeFile(f):
        fileArray = []
        for line in f:
            fileArray.append(line.strip())
        return fileArray

    @staticmethod
    def liner(rows, columns, delimiter):
        vectors = []
        for row in rows:
            vector = []
            tok = row.split(delimiter)
            for num in columns:
                vectors.append(float(tok[num]))
        return vectors

class linRegmain:
    def openfile(self, file):
        f = open(file)
        a = processFile.wholeFile(f)[1:]
        dataAvgandtemp = processFile.liner(a, [2,3], ";")
        self.xs = self.tempDiff(dataAvgandtemp)
        self.ys = processFile.liner(a,[1], ";")
        print self.xs
        print self.ys


    def tempDiff(self, vectors):
        tdArray = []
        for vector in vectors:
            tdArray.append([vector[0]-vector[1]])
        return tdArray

if __name__ == '__main__':
    LR = linRegmain()
    LR.openfile('djia_temp.csv')

Answer 1

liner() claims to return a list of vectors. It does not. You're making a list of float s:

vectors.append(float(tok[num]))

Therefore, when you call tempDiff() with the result, vector is a float , so vector[0] throws an exception.

I think this is what it's supposed to do: add each float to the current vector, then add the vector to the result:

@staticmethod
def liner(rows, columns, delimiter):
    vectors = []
    for row in rows:
        vector = []
        tok = row.split(delimiter)
        for num in columns:
            vector.append(float(tok[num])) # append to vector, not vectors
        vectors.append(vector)             # then append the vector to the result
    return vectors