selenium实现chrome分屏截图的合并

def test_capture(url, w_pix,h_pix):
    try:  
        self.driver.set_window_size(w_pix,h_pix)
        self.driver.get(url)            
        self.driver.implicitly_wait(5)
        i = 0
        img_list = []
        while i<30:
            js="var q=document.body.scrollTop="+ str(i*wap_pixs[pix][1])+";"
            self.driver.execute_script(js)
            time.sleep(1)
            js1 = "return document.body.scrollHeight-document.body.scrollTop"
            s= self.driver.execute_script(js1)
            if h_pix >= s:
                break
            else:
                self.driver.save_screenshot(str(i)+‘.png‘)
                img_list.append(str(i)+‘.png‘)
            i += 1
        image_merge(img_list)
　　except:
　　　　print ‘error‘

from PIL import Image
def image_merge(images, output_dir=‘‘, output_name=‘merge.jpg‘, restriction_max_width=None, restriction_max_height=None):  
    """垂直合并多张图片 
    images - 要合并的图片路径列表 
    ouput_dir - 输出路径 
    output_name - 输出文件名 
    restriction_max_width - 限制合并后的图片最大宽度，如果超过将等比缩小 
    restriction_max_height - 限制合并后的图片最大高度，如果超过将等比缩小 
    """  
    def image_resize(img, size=(1500, 1100)):  
        """调整图片大小 
        """  
        try:  
            if img.mode not in (‘L‘, ‘RGB‘):  
                img = img.convert(‘RGB‘)  
            img = img.resize(size)  
        except Exception, e:  
            pass  
        return img
    
    
    max_width = 0  
    total_height = 0  
    # 计算合成后图片的宽度（以最宽的为准）和高度  
    for img_path in images:  
        if os.path.exists(img_path):  
            img = Image.open(img_path)  
            width, height = img.size  
            if width > max_width:  
                max_width = width  
            total_height += height  
  
    # 产生一张空白图  
    new_img = Image.new(‘RGB‘, (max_width, total_height), 255)  
    # 合并  
    x = y = 0  
    for img_path in images:  
        if os.path.exists(img_path):  
            img = Image.open(img_path)  
            width, height = img.size  
            new_img.paste(img, (x, y))  
            y += height  
  
    if restriction_max_width and max_width >= restriction_max_width:  
        # 如果宽带超过限制  
        # 等比例缩小  
        ratio = restriction_max_height / float(max_width)  
        max_width = restriction_max_width  
        total_height = int(total_height * ratio)  
        new_img = image_resize(new_img, size=(max_width, total_height))  
  
    if restriction_max_height and total_height >= restriction_max_height:  
        # 如果高度超过限制  
        # 等比例缩小  
        ratio = restriction_max_height / float(total_height)  
        max_width = int(max_width * ratio)  
        total_height = restriction_max_height  
        new_img = image_resize(new_img, size=(max_width, total_height))  
      
    if not os.path.exists(output_dir):  
        os.makedirs(output_dir)  
    save_path = ‘%s/%s‘ % (output_dir, output_name)  
    new_img.save(save_path)  
    for img_path in images:  
        os.remove(img_path)
    return save_path