python如何生成验证码图片

想利用python做为后端生成一个验证码图片，并且能根据生成的验证码图片在前端请求接口时后端进行判断是否返回数据

1、首先利用PIL模块生成验证码图片，这个在百度或者CSDN中都可以直接搜到
2、其次利用flask模块的来对前端的请求做处理，同时可以使用flask_cors模块中的CORS方法做好跨域处理
3、最后就是处理发送给前端的数据


import os
import random
import base64
from io import BytesIO
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont


def random_color():
    c1 = random.randint(0, 255)
    c2 = random.randint(0, 255)
    c3 = random.randint(0, 255)
    return c1, c2, c3


def generate_picture(width=120, height=35):
    image = Image.new('RGB', (width, height), random_color())
    return image


def random_str():
    '''
    获取一个随机字符, 数字或小写字母
    :return:
    '''
    random_num = str(random.randint(0, 9))
    random_low_alpha = chr(random.randint(97, 122))
    random_char = random.choice([random_num, random_low_alpha])
    return random_char

def draw_str(count, image, font_size):
    """
    在图片上写随机字符
    :param count: 字符数量
    :param image: 图片对象
    :param font_size: 字体大小
    :return:
    """
    draw = ImageDraw.Draw(image)
    # 获取一个font字体对象参数是ttf的字体文件的目录，以及字体的大小
    font_file = os.path.join('Andale Mono.ttf')
    font = ImageFont.truetype(font_file, size=font_size)
    temp = []
    for i in range(count):
        random_char = random_str()
        draw.text((10+i*30, -2), random_char, random_color(), font=font)
        temp.append(random_char)

    valid_str = "".join(temp)    # 验证码
    return valid_str, image


def noise(image, width=120, height=35, line_count=3, point_count=20):
    '''

    :param image: 图片对象
    :param width: 图片宽度
    :param height: 图片高度
    :param line_count: 线条数量
    :param point_count: 点的数量
    :return:
    '''
    draw = ImageDraw.Draw(image)
    for i in range(line_count):
        x1 = random.randint(0, width)
        x2 = random.randint(0, width)
        y1 = random.randint(0, height)
        y2 = random.randint(0, height)
        draw.line((x1, y1, x2, y2), fill=random_color())

        # 画点
        for i in range(point_count):
            draw.point([random.randint(0, width), random.randint(0, height)], fill=random_color())
            x = random.randint(0, width)
            y = random.randint(0, height)
            draw.arc((x, y, x + 4, y + 4), 0, 90, fill=random_color())

    return image


def valid_code():
    """
    生成图片验证码,并对图片进行base64编码
    :return:
    """
    image = generate_picture()
    valid_str, image = draw_str(4, image, 35)
    image = noise(image)

    f = BytesIO()
    image.save(f, 'png')        # 保存到BytesIO对象中, 格式为png
    data = f.getvalue()
    f.close()

    encode_data = base64.b64encode(data)
    data = str(encode_data, encoding='utf-8')
    img_data = "data:image/jpeg;base64,{data}".format(data=data)
    return valid_str, img_data

if __name__ == '__main__':
    print(valid_code())

最终效果：

img