如何将Python代码转换为Robot Framework

我正在尝试使CAPTCHA自动化，为此我也编写了python代码。现在，我陷入了困境，即无法通过创建自定义库在Robot Framework中调用它。

from PIL import Image
import string
import json
import os
import time
import pytesseract
import cv2
import numpy as np
import re
from tesserocr import PyTessBaseAPI,PSM, OEM
import time
import logging

captcha_url = "http://www.mca.gov.in/mcafoportal/getCapchaImage.do"
regex = re.compile(r'[\n\r\t ]')#special char plus space

def get_captcha2(session):
    res = session.get(captcha_url, timeout = 10)
    with open("a.jpg", "wb") as f: f.write(res.content)
    img = Image.open("a.jpg")
    captcha = pytesseract.image_to_string(img, config='--psm 8 --oem 0 -c tessedit_char_whitelist=abcdefghijklmnopqrstuvwxyz')
    logging.info("cap: %s"%captcha)
    while not (captcha.islower() and captcha.isalpha() and len(captcha) in  [6,7]):
        time.sleep(.05)
        res = session.get(captcha_url)
        with open("a.jpg", "wb") as f: f.write(res.content)
        img = Image.open("a.jpg")
        captcha = pytesseract.image_to_string(img, config='--psm 8')
        logging.info("cap: %s"%captcha)
    return captcha



def get_captcha(req):
    api = PyTessBaseAPI(psm=PSM.SINGLE_WORD, oem = 0)
    api.SetVariable("tessedit_char_whitelist", "abcdefghijklmnopqrstuvwxyz")
    res = req.get(captcha_url, timeout = 10)
    #with open("a.jpg", "wb") as f: f.write(res.content)
    clean_captcha_image(api, res.content)
    captcha = regex.sub("", api.GetUTF8Text())
    conf = api.MeanTextConf()
    cnt = 0
    while (len(captcha) not in  [6,7] or conf<=70) and cnt<=3:
        res = req.get(captcha_url, timeout = 10)
        clean_captcha_image(api, res.content)
        captcha = regex.sub("", api.GetUTF8Text())
        conf = api.MeanTextConf()
        cnt += 1
    return captcha


def break_point(arr):
    for i,n in arr:
        if n:
            break
    return i

def convert_numpy_ipl(trimmed):
    h,w = trimmed.shape
    c = 1
    iplimage = cv.CreateImageHeader((w,h), cv.IPL_DEPTH_8U, c)
    cv.SetData(iplimage, trimmed.tostring(),trimmed.dtype.itemsize * c * (w))
    return iplimage

def clean_captcha_image(api, c_content):
    try:
        arr = np.fromstring(c_content, np.uint8)
        image = cv2.imdecode(arr,0)
        th = cv2.threshold(image,50,255,cv2.THRESH_BINARY|cv2.THRESH_OTSU)[1]

        iplimage = Image.fromarray(th)
        api.SetImage(iplimage)
    except Exception as e:
        print("Unexpected error on clean ",e)


def parse_captcha(filename):
    return pytesseract.image_to_string(Image.open(filename))

if __name__ == "__main__":
    import requests
    session = requests.Session()
    session.headers = {"User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Safari/537.36"}
    get_captcha2(session)

我尝试使用Robot Framework自动执行相同操作，但由于会话超时而失败。当我尝试下载图像时，验证码已更改。