retina屏幕截取验证码

        # 截取全屏
        picture1 = str('yzm1')+'.png'
        self.driver.save_screenshot(picture1)
        # 定位验证码
        code = self.driver.find_element_by_xpath('xxx')
        print(code.location)
        # 定位像素
        left = code.location['x']
        top = code.location['y']
        right = code.size['width']+left
        height = code.size['height']+top
        #    retina屏幕
        dpr = self.driver.execute_script('return window.devicePixelRatio')
        print(dpr)
        im = Image.open(picture1)
        code_img = im.crop((left * dpr, top * dpr, right * dpr, height * dpr))
        picture2 = str('yzm2')+'.png'
        code_img.save(picture2)