Python学习---抽屉框架分析[小评论分析]0315

注： 此处的小评论涉及数据库操作

初级小评论代码

settings.py

INSTALLED_APPS = [
   ...
 'app01',   # 注册app
]
STATICFILES_DIRS = (os.path.join(BASE_DIR, "statics"),)  # 现添加的配置,这里是元组，注意逗号
TEMPLATES = [
   ...
   'DIRS': [os.path.join(BASE_DIR, 'templates')],
]

urls.py

from django.contrib import admin
from django.urls import path
from django.conf.urls import url, include
from app01 import views
urlpatterns = [
    # 评论
  url('comment/', views.Node.Comment)
]

views.py

from django.shortcuts import render
from django.shortcuts import redirect
from django.shortcuts import HttpResponse
from app01 import models

class Node:
    @staticmethod
    def digui(ret, row):
        for item in ret:
            if row['parent_id'] == item['id']:
                row['children'] = []
                item['children'].append(row)
                break
            else:
                Node.digui(item['children'], row)
    @staticmethod
    def create_commen_tree(comment_list):
        ret = []
        '''
        ret=[
                {'id':1, 'content':'Python', 'user':'AAA', 'parent_id': None, 'children':[]},
                {'id':2, 'content':'JAVA', 'user':'AAA', 'parent_id': None,   'children':[]},
                {'id':3, 'content':'C++', 'user':'AAA', 'parent_id': None,    'children':[]}
            ]
        '''
        for row in comment_list:
            if not row['parent_id']:
                row['children'] = []
                ret.append(row)
            else:
                Node.digui(ret, row)
        return ret

    # 评论
    def Comment(request):
        '''
        【标准】方式一：这里是从数据库内取值
        news_id = 1
        # 获取新闻id=1的新闻，页面不能直接循环，否则显示不出来层级关系
        commen_list = models.Comment.objects.filter(news_id=news_id)
        for row in commen_list:
            print(row.id, row.content, row.userInfo.name, row.parent_id)

        return HttpResponse("OK")
        '''
        # 方式二： 这里是模仿来实现评论的级别关系
        comment_list = [
            {'id':1, 'content':'Python', 'user':'AAA', 'parent_id': None},
            {'id':2, 'content':'JAVA', 'user':'AAA', 'parent_id': None},
            {'id':3, 'content':'C++', 'user':'AAA', 'parent_id': None},
            {'id':4, 'content':'PHP', 'user':'BBB', 'parent_id': 1},
            {'id':5, 'content':'HTML', 'user':'CCC', 'parent_id': 1},
            {'id':6, 'content':'CSS', 'user':'DDD', 'parent_id': 4},
            {'id':7, 'content':'JavaScript', 'user':'EEE', 'parent_id': 2},
            {'id':8, 'content':'Python', 'user':'FFF', 'parent_id': 3},
            {'id':9, 'content':'C#', 'user':'GGG', 'parent_id': 2},
            {'id':10, 'content':'Shell', 'user':'HHH', 'parent_id': 4},
            {'id':11, 'content':'C语言', 'user':'XXX', 'parent_id': 6},
        ]
        comment_tree = Node.create_commen_tree(comment_list)
        for item in comment_tree:
            print(item)
        return HttpResponse("OK")

models.py

from django.db import models

# Create your models here.

# 新闻表
class News(models.Model):
    title = models.CharField(max_length=32)

# 用户表
class UserInfo(models.Model):
    name = models.CharField(max_length=32)

# 评论表
class Comment(models.Model):
    content = models.CharField(max_length=150)
    userInfo = models.ForeignKey("UserInfo", on_delete=True)
    news = models.ForeignKey("News", on_delete=True)
    parent = models.ForeignKey("self", on_delete=True, related_name='o', null=True)
    ctime = models.DateTimeField(auto_now_add=True, null=True)

页面显示；

image

image

初始化数据库

python manage.py makemigrations

python manage.py migrate

高级小评论代码

原理解析：

因为li[列表]是引用类型，所以v和li引用同一个地址，v增加后li也同时增加

li = [
    [1,2,3,4,5],
    [1,2,3,4,5,6],
]
v = li
v.append([000,111,222])
print(li)
print(v)

image

同上原理,每个字典更改后，其内部的内容包括引用的内容都会修改

li = [
    {'id': 10, 'content': 'Shell', 'user': 'HHH', 'parent_id': 4},
    {'id': 11, 'content': 'C语言', 'user': 'XXX', 'parent_id': 6},
]
v = li
for item in li:
    item.update({'children' : []})   # 每个列表里面添加children属性，有则更改，无责添加
print('li里的元素：
', li)

# 为每隔row添加children属性
for row in li:
    if row['id'] == 11:
        row['children'].append(row)

li[1]['user'] = 'FTL'  # 此时li[1]里面的内容全部修改了包括内部children中的name
# 在item里的children元素添加item内容
for item in li:
    print('children添加元素：
', item, item['children'])

内容显示：

image

小评论高级算法：

comment_list = [
            {'id':1, 'content':'Python', 'user':'AAA', 'parent_id': None},
            {'id':2, 'content':'JAVA', 'user':'AAA', 'parent_id': None},
            {'id':3, 'content':'C++', 'user':'AAA', 'parent_id': None},
            {'id':4, 'content':'PHP', 'user':'BBB', 'parent_id': 1},
            {'id':5, 'content':'HTML', 'user':'CCC', 'parent_id': 1},
            {'id':6, 'content':'CSS', 'user':'DDD', 'parent_id': 4},
            {'id':7, 'content':'JavaScript', 'user':'EEE', 'parent_id': 2},
            {'id':8, 'content':'Python', 'user':'FFF', 'parent_id': 3},
            {'id':9, 'content':'C#', 'user':'GGG', 'parent_id': 2},
            {'id':10, 'content':'Shell', 'user':'HHH', 'parent_id': 4},
            {'id':11, 'content':'C语言', 'user':'XXX', 'parent_id': 6},
        ]
'''
方法一： for循环，效率低
ret = []
for it in comment_list:
    it.update({'children': []})
for item in comment_list:
    current_row = item
    current_row_parentId = current_row['parent_id']
    if not current_row_parentId:
        ret.append(current_row)
    else:
        for row in comment_list:   # 效率低，从头到尾又循环了一遍
            if row['id'] == current_row_parentId:
                row['children'].append(item)
print(ret)
'''
# 方法二： 利用字典的get效率更高，因为字典的key会转换为哈希字符串，get相当于根据sql里面的索引查找
ret = []
comment_list_dict={}
for item in comment_list:
    item.update({"children":[]})
 #有则更改，无责添加： comment_list_dict={1:{'id':1, 'content':'Python', 'user':'AAA', 'parent_id': None},}
    comment_list_dict[item['id']]=item
for row in comment_list:
    current_now_parentID = row['parent_id']
    parent_row = comment_list_dict.get(current_now_parentID)  # 找到了父级row
    if not parent_row:
        ret.append(row)
    else:
        parent_row['children'].append(row)            # 直接给父级row的children添加当前元素
print(ret)

image

小评论高级完整版[前台处理数据，推荐使用]

settings.py

INSTALLED_APPS = [
   ...
 'app01',   # 注册app
]
STATICFILES_DIRS = (os.path.join(BASE_DIR, "statics"),)  # 现添加的配置,这里是元组，注意逗号
TEMPLATES = [
   ...
   'DIRS': [os.path.join(BASE_DIR, 'templates')],
]

urls.py

from django.contrib import admin
from django.urls import path
from django.conf.urls import url, include
from app01 import views
urlpatterns = [
   # 评论
 url('comment/', views.comment),
 url('index/', views.index),
]

views.py

from django.shortcuts import render, redirect, HttpResponse
from app01 import models

#小评论高级算法
def comment(request):
    '''
        数据库的操作：
        nid = request.GET.get('nid')
        comment_list=models.obects.filter(nid=nid).values('id',...)  # 利用value进行字段内容的获取
        commont_list --> ret  [进行树形结构的转换，这里直接用固定的内容演示]
    '''
    comment_list = [
                {'id':1, 'content':'Python', 'user':'AAA', 'parent_id': None},
                {'id':2, 'content':'JAVA', 'user':'AAA', 'parent_id': None},
                {'id':3, 'content':'C++', 'user':'AAA', 'parent_id': None},
                {'id':4, 'content':'PHP', 'user':'BBB', 'parent_id': 1},
                {'id':5, 'content':'HTML', 'user':'CCC', 'parent_id': 1},
                {'id':6, 'content':'CSS', 'user':'DDD', 'parent_id': 4},
                {'id':7, 'content':'JavaScript', 'user':'EEE', 'parent_id': 2},
                {'id':8, 'content':'Python', 'user':'FFF', 'parent_id': 3},
                {'id':9, 'content':'C#', 'user':'GGG', 'parent_id': 2},
                {'id':10, 'content':'Shell', 'user':'HHH', 'parent_id': 4},
                {'id':11, 'content':'C语言', 'user':'XXX', 'parent_id': 6},
            ]
    ret = []
    comment_list_dict={}
    for item in comment_list:
        item.update({"children":[]})
        #  有则更改，无责添加： comment_list_dict={1:{'id':1, 'content':'Python', 'user':'AAA', 'parent_id': None},}
        comment_list_dict[item['id']]=item

    for row in comment_list:
        current_now_parentID = row['parent_id']
        parent_row = comment_list_dict.get(current_now_parentID)  # 找到了父级row
        if not parent_row:
            ret.append(row)
        else:
            parent_row['children'].append(row)       # 直接给父级row的children添加当前元素
    print(ret)
    import json
    return HttpResponse(json.dumps(comment_list))

def index(request):
    return render(request, 'index.html')

models.py[未用到，静态数据源]

from django.db import models
# Create your models here.
# 新闻表
class News(models.Model):
    title = models.CharField(max_length=32)
# 用户表
class UserInfo(models.Model):
    name = models.CharField(max_length=32)
# 评论表
class Comment(models.Model):
    content = models.CharField(max_length=150)
    userInfo = models.ForeignKey("UserInfo", on_delete=True)
    news = models.ForeignKey("News", on_delete=True)
    parent = models.ForeignKey("self", on_delete=True, related_name='o', null=True)
    ctime = models.DateTimeField(auto_now_add=True, null=True)

templates/comment.html

<!DOCTYPE html>
<html lang="en">
<head>    <meta charset="UTF-8">  </head>
<body> </body>
</html>

templates/index.html

<!DOCTYPE html>
<html lang="en">
<head>  <meta charset="UTF-8">
    <style>
        .comment-box {
            margin-left: 10px;
        }
    </style>
</head>
<body>
    <div class="item">
        <h2>[静态演示效果]</h2>
        <a nid="17" class="com">评论</a>
        {#comment-box表示一个评论#}
        <div class="comment-list">
            <div class="comment-box">
            <span>Python开发</span>
            <div class="comment-box">
                <span>Java开发</span>
                <div class="comment-box">
                <span>C开发</span>
            </div>
            </div>
             <div class="comment-box">
                <span>PHP开发</span>
            </div>
        </div>
            <div class="comment-box">
            <span>手机厂商</span>
            <div class="comment-box">
                <span>Huawei</span>
                <div class="comment-box">
                <span>XiaoMi</span>
            </div>
            </div>
             <div class="comment-box">
                <span>Apple</span>
            </div>
        </div>
        </div>
    </div><hr>
    <div class="item">
        <h3>动态演示效果，点击显示评论</h3>
        <a nid="18"  class="com">评论</a>
    </div><hr>
</body>
<script src="/static/jquery-2.1.4.min.js"></script>
<script>
    // 页面加载完成后实现绑定小姑
    $(function () {
        bindCommentEvent();
    });

    function bindCommentEvent() {
        $(".com").click(function () {
            var news_id = $(this).attr('nid');
            console.log(news_id);
            var $this = $(this);
            $.ajax({
                url:'/comment/',
                type:'GET',
                // 一个date引发的错误
                data: {nid:news_id},
                dataType: "JSON",
                success: function (args) {
                    console.log(args);
                    create_tree(args, $this);
                }
            })
        })
    }
    // 递归
    function digui(child_data) {
        var html = "";
        $.each(child_data, function (k1, v1) {
            var b = '<div class="comment-box"><span>';
            b += v1.content;
            b += '</span>';
            son = digui(v1.children);
            b += son;
            b += '</div>';
            html += b;
        });
        console.log("HTML:",html)
        return html;
    }
    function create_tree(data,$this) {
        var html = '<div class="comment-list">';
        {#  注意这里是在函数内获取到key,value,然后从value里面获取内容#}
        $.each(data, function (k, v) {
            var a = '<div class="comment-box"><span>';
            a += v.content + "</span>";
            // 添加子评论
            var child = digui(v.children);
            console.log(child);
            a += child;
            a +='</div>';
            html += a;
        });
        html += '</div>';
        console.log($this);
        $this.append(html);
    }
</script>
</html>

页面显示；

image

image

初始化数据库

python manage.py makemigrations
python manage.py migrate

小评论最终版[后台进行tempaltetags来处理递归数据，不推荐]

settings.py

INSTALLED_APPS = [
   ...
 'app01',   # 注册app
]
STATICFILES_DIRS = (os.path.join(BASE_DIR, "statics"),)  # 现添加的配置,这里是元组，注意逗号
TEMPLATES = [
   ...
   'DIRS': [os.path.join(BASE_DIR, 'templates')],
]

urls.py

from django.contrib import admin
from django.urls import path
from django.conf.urls import url, include
from app01 import views
urlpatterns = [
   # 评论
 url('comment/', views.comment),
 url('index/', views.index),
]

views.py

from django.shortcuts import render, redirect, HttpResponse
from app01 import models

#小评论高级算法
def comment(request):
    '''
        数据库的操作：
        nid = request.GET.get('nid')
        comment_list=models.obects.filter(nid=nid).values('id',...)  # 利用value进行字段内容的获取
        commont_list --> ret  [进行树形结构的转换，这里直接用固定的内容演示]
    '''
    comment_list = [
                {'id':1, 'content':'Python', 'user':'AAA', 'parent_id': None},
                {'id':2, 'content':'JAVA', 'user':'AAA', 'parent_id': None},
                {'id':3, 'content':'C++', 'user':'AAA', 'parent_id': None},
                {'id':4, 'content':'PHP', 'user':'BBB', 'parent_id': 1},
                {'id':5, 'content':'HTML', 'user':'CCC', 'parent_id': 1},
                {'id':6, 'content':'CSS', 'user':'DDD', 'parent_id': 4},
                {'id':7, 'content':'JavaScript', 'user':'EEE', 'parent_id': 2},
                {'id':8, 'content':'Python', 'user':'FFF', 'parent_id': 3},
                {'id':9, 'content':'C#', 'user':'GGG', 'parent_id': 2},
                {'id':10, 'content':'Shell', 'user':'HHH', 'parent_id': 4},
                {'id':11, 'content':'C语言', 'user':'XXX', 'parent_id': 6},
            ]
    ret = []
    comment_list_dict={}
    for item in comment_list:
        item.update({"children":[]})
        #  有则更改，无责添加： comment_list_dict={1:{'id':1, 'content':'Python', 'user':'AAA', 'parent_id': None},}
        comment_list_dict[item['id']]=item

    for row in comment_list:
        current_now_parentID = row['parent_id']
        parent_row = comment_list_dict.get(current_now_parentID)  # 找到了父级row
        if not parent_row:
            ret.append(row)
        else:
            parent_row['children'].append(row)       # 直接给父级row的children添加当前元素
    print(ret)
          return render(request,'comment.html', {"ret":ret})

def index(request):
    return render(request, 'index.html')

models.py[未用到，静态数据源]

from django.db import models
# Create your models here.
# 新闻表
class News(models.Model):
    title = models.CharField(max_length=32)
# 用户表
class UserInfo(models.Model):
    name = models.CharField(max_length=32)
# 评论表
class Comment(models.Model):
    content = models.CharField(max_length=150)
    userInfo = models.ForeignKey("UserInfo", on_delete=True)
    news = models.ForeignKey("News", on_delete=True)
    parent = models.ForeignKey("self", on_delete=True, related_name='o', null=True)
    ctime = models.DateTimeField(auto_now_add=True, null=True)

App01/tempalatetags/hhh.py

from django import template
from django.utils.safestring import mark_safe
register = template.Library()

def diGui(children_list):
    html = ""
    for cv in children_list:
        b = '<div class="comment-box"><span>'
        b += cv['content'] + "</span>"
        b += diGui(cv['children'])
        b += "</div>"
        html += b
    return html

@register.simple_tag
def create_tree(comment_list):
    html = '<div class="comment-list">'
    for v in comment_list:
        a = '<div class="comment-box"><span>'
        a += v['content'] + "</span>"
        a += diGui(v['children'])
        a += "</div>"
        html += a
    return mark_safe(html) # 不添加界面只显示源代码，并不进行html渲染

templates/comment.html

{% load hhh %}
{% create_tree ret %}

templates/index.html

<!DOCTYPE html>
<html lang="en">
<head>  <meta charset="UTF-8">
    <style>
        .comment-box {
            margin-left: 10px;
        }
    </style>
</head>
<body>
    <div class="item">
        <h2>[静态演示效果]</h2>
        <a nid="17" class="com">评论</a>
        {#comment-box表示一个评论#}
        <div class="comment-list">
            <div class="comment-box">
            <span>Python开发</span>
            <div class="comment-box">
                <span>Java开发</span>
                <div class="comment-box">
                <span>C开发</span>
            </div>
            </div>
             <div class="comment-box">
                <span>PHP开发</span>
            </div>
        </div>
            <div class="comment-box">
            <span>手机厂商</span>
            <div class="comment-box">
                <span>Huawei</span>
                <div class="comment-box">
                <span>XiaoMi</span>
            </div>
            </div>
             <div class="comment-box">
                <span>Apple</span>
            </div>
        </div>
        </div>
    </div><hr>
    <div class="item">
        <h3>动态演示效果，点击显示评论</h3>
        <a nid="18"  class="com">评论</a>
    </div><hr>
</body>
<script src="/static/jquery-2.1.4.min.js"></script>
<script>
    // 页面加载完成后实现绑定小姑
    $(function () {
        bindCommentEvent();
    });

    function bindCommentEvent() {
        $(".com").click(function () {
            var news_id = $(this).attr('nid');
            console.log(news_id);
            var $this = $(this);
            $.ajax({
                url:'/comment/',
                type:'GET',
                // 一个date引发的错误
                data: {nid:news_id},
                dataType: "html",
                success: function (args) {
                    console.log('HHH');
                    console.log(args);
                    {# create_tree(args, $this);#}
                    $this.after(args);
                }
            })
        })
    }
    /**
    function digui(child_data) {
        var html = "";
        $.each(child_data, function (k1, v1) {
            var b = '<div class="comment-box"><span>';
            b += v1.content;
            b += '</span>';
            son = digui(v1.children);
            b += son;
            b += '</div>';
            html += b;
        });
        console.log("HTML:",html)
        return html;
    }

    function create_tree(data,$this) {
        var html = '<div class="comment-list">';
        {#  注意这里是在函数内获取到key,value,然后从value里面获取内容#}
        $.each(data, function (k, v) {
            var a = '<div class="comment-box"><span>';
            a += v.content + "</span>";
            // 添加子评论
            var child = digui(v.children);
            console.log(child);
            a += child;
            a +='</div>';
            html += a;
        });
        html += '</div>';
        console.log($this);
        $this.after(html);
    }
    **/
</script>
</html>

页面显示；

image

初始化数据库

python manage.py makemigrations
python manage.py migrate
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原文地址：https://www.cnblogs.com/ftl1012/p/9417356.html