最近有小伙伴提问：能否说下web验证的原理，感觉文字描述不清楚，于是就用代码简单的演示下：此代码是需要依赖：

sanic==19.9.0Pillow==7.0.0

import randomimport stringimport uuidimport base64import platformfrom PIL import Image, ImageDraw,ImageFontfrom io import BytesIOfrom sanic import Sanicfrom sanic.response import HTTPResponse,textfrom sanic.views import HTTPMethodViewapp = Sanic()session = {}class VerifyCode:    def __init__(self, numbers:int):        """        指定:生成的数量        """        self.number = numbers    def draw_lines(self, draw, num, width, height):        """划线"""        x1 = random.randint(0, width / 2)        y1 = random.randint(0, height / 2)        x2 = random.randint(0, width)        y2 = random.randint(height / 2, height)        draw.line(((x1, y1), (x2, y2)), fill='black', width=1)    def random_color(self):        """随机颜色"""        return (random.randint(32, 127), random.randint(32, 127), random.randint(32, 127))    def gene_text(self):        """生成验证码"""        return "".join(random.sample(string.ascii_letters+string.digits, self.number))    def get_verify_code(self):        """        draw.text()：            文字的绘制，第一个参数指定绘制的起始点(文本的左上角所在位置)，第二个参数指定文本内容，第三个参数指定文本的颜色，第四个参数指定字体(通过ImageFont类来定义)        """        code = self.gene_text()        width, height = 130, 30        im = Image.new("RGB", (width, height), "white")        # 这里指定字体的路径        sysstr = platform.system()        font = None        if sysstr == "Windows":            font = ImageFont.truetype("C:WINDOWSFontsSTXINGKA.TTF", 25)        elif sysstr == "Darwin":            font = ImageFont.truetype('/Library/Fonts/AppleMyungjo.ttf', 25)        draw = ImageDraw.Draw(im)        for item in range(self.number):            draw.text((5+random.randint(-5,5)+23*item, 5+random.randint(-5, 5)), text=code[item],                      fill=self.random_color(), font=font)            self.draw_lines(draw, self.number, width, height)        return im, codeclass SimpleView(HTTPMethodView):    body = """                                    登录                    

{error}

验证码

验证

""" async def get(self, request): return self.response(error="") async def post(self, request): uuid = request.cookies.get("uuid", "1") verfy_code = request.form.get("code", "2").lower() code = session.get(uuid, "").lower() if code == verfy_code: return text('验证码正确') return self.response(error='') def response(self, error): im, code = VerifyCode(5).get_verify_code() buf = BytesIO() im.save(buf, "jpeg") buf_str = buf.getvalue() base64_data = base64.b64encode(buf_str).decode() id = uuid.uuid1().__str__() session[id] = code body = self.body.format(base64_data=base64_data, error=error) response = HTTPResponse(body, content_type="text/html; charset=utf-8") response.cookies["uuid"] = id return responseapp.add_route(SimpleView.as_view(), '/code')if __name__ == "__main__": app.run(host="0.0.0.0", port=8000)

只是简单的实现了验证码，没有实现点击刷新，点击刷新的原理不难：异步请求+刷新接口就好了，记得更新对应的session的key里面的value

0人点赞

随笔