Solves simple captchas has only digits

captcha_solver.py

import cv2
import pytesseract
from os import walk

pytesseract.pytesseract.tesseract_cmd = r'/usr/local/bin/tesseract'
config = u" -c tessedit_char_whitelist=0123456789 --oem 3 --psm 7 -l digits"

def solve(file):
	image_file_name = './data/' + file
	im = cv2.imread(image_file_name)
	ret,thresh1 = cv2.threshold(im, 150, 255, cv2.THRESH_BINARY_INV)
	cv2.imwrite('/tmp/temp.jpg', thresh1)
	ocr = pytesseract.image_to_string('/tmp/temp.jpg', config=config).replace(' ', '').replace('/', '7').replace('?', '7')
	expected = image_file_name.replace('.jpg', '').replace('./data/', '')

	if ocr == expected:
		print('\33[2;32m')			
		print('-----------------------------------')
		print('OCR\t:' + ocr)
		print('EXPT\t:' + expected)

	else:
		print('\33[1;31m')			
		print('-----------------------------------')
		print('OCR\t:' + ocr)
		print('EXPT\t:' + expected)	
	print('\33[m')

files = []
for (dirpath, dirnames, filenames) in walk('./data'):
    files.extend(filenames)
    break

for file in files:
	solve(file)