captcha cracker challenge in hackerrank

captcha_main.py

#build a model with your favourite classifier !
from sklearn.linear_model import LogisticRegression

#read the raw training data
data = readData(directory)
#prepare the training data from the raw data
trainingdata =  prepareTrainingData(data)

#create the classifier
clf = LogisticRegression()
clf.fit(trainingdata[0], trainingdata[1])

#now the classifier can be used to predict any new captcha!

prep_data.py

def prepareTrainingData(data):
    train_x = []
    train_y = []
    #set a threshold for value to remove the background
    threshold = 100
    for d in data:
        img = d[0]
        output = list(d[1])
        i=0
        #cut the image into 5 pices !
        startLocX = 7
        endLocX = 21
        startLocY = 6
        increment = 8
        for i in range(5):
            char = img[startLocX:endLocX,startLocY:startLocY+increment]
            #remove the background by thresholding
            #turn the background pixels to white
            char[char > threshold] = 255
            startLocY = startLocY + increment + 1
            train_x.append(char.ravel())
            train_y.append(output[i])
    return (train_x,train_y)

read_data.py

import os
import numpy as np

def readImageFile(imgLoc):
    '''
    Reads one image file from imgLoc
    '''
    pixels = []
    with open(imgLoc) as f:
        next(f)
        for line in f:
            row = []
            for p in line.split(" "):
                vals = [int(val) for val in p.split(",")]
                row.append(sum(vals)/len(vals))
            pixels.append(row)
    return np.array(pixels,dtype = np.uint8)

def readData(directory):
    '''
    Reads all captcha files and their labels from directory. directory should have this structure
    as provided by the problem:
    -directory
        -input
            -0.txt
            -1.txt
            -...
        -output
            -0.txt
            -1.txt
            -...
    '''
    images = []
    for root, dirs, files in os.walk(directory+"input/", topdown=False):
        files = [fi for fi in files if fi.endswith(".txt")]
        for name in files:
            outputfileName =  "output"+str(name[5:].split(".")[0])+".txt"
            imgdata = readImageFile(os.path.join(root, name))
            with open(directory+"output/"+outputfileName) as outf:
                output = next(outf).strip()
            images.append((imgdata,output))
    return images