Generate verification code

from captcha.image import ImageCaptcha
import random
import numpy as np
from PIL import Image
import matplotlib.pyplot as plt

number = ['0','1','2','3','4','5','6','7','8','9']
ALPH = []
alph = []
for i in range(65,91):
    ALPH.append(chr(i))
    
for i in ALPH:
    alph.append(i.swapcase())

def random_captcha_text(size=4,charset=number+alph+ALPH):
    captcha_text = []
    for i in range(size):
        c = random.choice(charset)
        captcha_text.append(c)
    return captcha_text

def gen_captcha_image():
    image = ImageCaptcha()
    captcha_text = random_captcha_text()
    captcha_text = ''.join(captcha_text)
    captchaInfo = image.generate(captcha_text)
#    print(captchaInfo)
    
    captcha_image = Image.open(captchaInfo)
    captcha_image = np.array(captcha_image)
    
    return captcha_text,captcha_image

    
    
if __name__ == '__main__':    
    text, image = gen_captcha_image()  
    print(text)
#    print(image)
    f = plt.figure()
    ax = f.add_subplot(111)
    ax.text(0.1, 0.9, text, ha='center',va='center')
    plt.imshow(image)
    plt.show()