python實現網站分頁

原文鏈接：https://blog.csdn.net/weixin_36380516/article/details/80295101

在web開發中，Flask web項目中實現分頁，使用py編寫。
首先，自定義一個分頁工具類page_utils：

    
   


    class Pagination(object):
    	def __init__(self, current_page, total_count, base_url, params, per_page_count=5, max_pager_count=11):
        try:
            current_page = int(current_page)
        except Exception as e:
            current_page = 1
        if current_page <= 0:
            current_page = 1
        self.current_page = current_page
        # 數據總條數
        self.total_count = total_count

        # 每頁顯示10條數據
        self.per_page_count = per_page_count

        # 頁面上應該顯示的最大頁碼
        max_page_num, div = divmod(total_count, per_page_count)
        if div:
            max_page_num += 1
        self.max_page_num = max_page_num

        # 頁面上默認顯示11個頁碼（當前頁在中間）
        self.max_pager_count = max_pager_count
        self.half_max_pager_count = int((max_pager_count - 1) / 2)

        # URL前綴
        self.base_url = base_url

        # request.GET
        import copy
        params = copy.deepcopy(params)
        get_dict = params.to_dict()

        self.params = get_dict

    @property
    def start(self):
        return (self.current_page - 1) * self.per_page_count

    @property
    def end(self):
        return self.current_page * self.per_page_count

    def page_html(self):
        # 如果總頁數 <= 11
        if self.max_page_num <= self.max_pager_count:
            pager_start = 1
            pager_end = self.max_page_num
        # 如果總頁數 > 11
        else:
            # 如果當前頁 <= 5
            if self.current_page <= self.half_max_pager_count:
                pager_start = 1
                pager_end = self.max_pager_count
            else:
                # 當前頁 + 5 > 總頁碼
                if (self.current_page + self.half_max_pager_count) > self.max_page_num:
                    pager_end = self.max_page_num
                    pager_start = self.max_page_num - self.max_pager_count + 1  # 倒這數11個
                else:
                    pager_start = self.current_page - self.half_max_pager_count
                    pager_end = self.current_page + self.half_max_pager_count

        page_html_list = []
        # {source:[2,], status:[2], gender:[2],consultant:[1],page:[1]}
        # 首頁
        self.params['page'] = 1
        first_page = '<li><a href="%s?%s">首頁</a></li>'  % (self.base_url, urlencode(self.params),)
        page_html_list.append(first_page)
        # 上一頁
        self.params["page"] = self.current_page - 1
        if self.params["page"] < 1:
            pervious_page = '<li class="disabled"><a href="%s?%s" aria-label="Previous">上一頁</span></a></li>'%(self.base_url, urlencode(self.params))
        else:
            pervious_page = '<li><a href = "%s?%s" aria-label = "Previous" >上一頁</span></a></li>' % (
            self.base_url, urlencode(self.params))
        page_html_list.append(pervious_page)
        # 中間頁碼
        for i in range(pager_start, pager_end + 1):
            self.params['page'] = i
            if i == self.current_page:
                temp = '<li class="active"><a href="%s?%s">%s</a></li>' % (self.base_url, urlencode(self.params), i,)
            else:
                temp = '<li><a href="%s?%s">%s</a></li>' % (self.base_url, urlencode(self.params), i,)
            page_html_list.append(temp)

        # 下一頁
        self.params["page"] = self.current_page + 1
        if self.params["page"] > self.max_page_num:
            self.params["page"] = self.current_page
            next_page = '<li class="disabled"><a href = "%s?%s" aria-label = "Next">下一頁</span></a></li >' % (self.base_url, urlencode(self.params))
        else:
            next_page = '<li><a href = "%s?%s" aria-label = "Next">下一頁</span></a></li>' % (
            self.base_url, urlencode(self.params))
        page_html_list.append(next_page)

        # 尾頁
        self.params['page'] = self.max_page_num
        last_page = '<li><a href="%s?%s">尾頁</a></li>' % (self.base_url, urlencode(self.params),)
        page_html_list.append(last_page)

        return ''.join(page_html_list)

自定義方法中的參數：
current_page——表示當前頁。
total_count——表示數據總條數。
base_url——表示分頁URL前綴，請求的前綴獲取可以通過Flask的request.path方法，無需自己指定。
例如：我們的路由方法爲@app.route(’/test’)，request.path方法即可獲取/test。
params——表示請求傳入的數據，params可以通過request.args動態獲取。
例如：我們鏈接點擊爲：http://localhost:5000/test?page=10，此時request.args獲取數據爲ImmutableMultiDict([(‘page’, u’10’)])
per_page_count——指定每頁顯示數。
max_pager_count——指定頁面最大顯示頁碼

flask一個簡單實戰：

@application.route('/admin/blog-center/blogmanage')
@login_required
def blog_center_blogmanage():
    #分頁的對象
    li = []
    #從數據庫中獲得所有博文
    blognums = Blog.query.count()
    #以時間倒序的方式排列
    blogs=Blog.query.order_by(Blog.create_time.desc())
    #li列表內裝的是每一條博文
    for i in range(0, blognums):
        li.append(blogs[i])
    #per_page_count是每一頁最多顯示的條數    
    pager_obj = Pagination(request.args.get("page", 1), len(li), request.path, request.args, per_page_count=5)
    index_list = li[pager_obj.start:pager_obj.end]
    html = pager_obj.page_html()
    return render_template('admin/blog-center-blogmanage.html',index_list=index_list, html=html)