转json只能是字典形式,单独对象不能转
递归:自己调用自己,如果用循环不知道有多少层,不好控制。
费波纳切:
def b(n): if n==2 or n==1: return 1 return b(n-1)+b(n-2)#n:2 b(1)+b(0)=2 num=int(input('请输入一个正整数:')) res=b(num) print(res)
model分为分类表、商品表两种。
from django.db import models from datetime import datetime # Create your models here. #分类表 class Category(models.Model): cname=models.CharField(max_length=30,null=False) parent=models.ForeignKey('Category',on_delete=None) class Meta(): db_table='category' #商品表 class Goods(models.Model): gname=models.CharField(max_length=50,null=False) price=models.FloatField() sum=models.IntegerField()#库存 count=models.IntegerField()#进货数量 createTime=models.DateTimeField(default=datetime.now())#进货时间 category=models.ForeignKey('Category',on_delete=None) class Meta(): db_table='Goods'
对象转json,要先转成字典:
from django.shortcuts import render,HttpResponse import json from django.views.decorators.csrf import csrf_exempt import pymysql from .models import Category,Goods from datetime import datetime # Create your views here. @csrf_exempt#导入csrf def queryTree(request): id = request.POST.get('id')#获取商品id global categorySet#获取全局变量 if id is None:#刚进去,没有点,显示父级树 categorySet = Category.objects.filter(parent_id=None) else: categorySet = Category.objects.filter(parent_id=id)#点一下父级树,子集出来 list=[]#编辑json格式 for category in categorySet: dict={} dict['id']=category.id dict['text']=category.cname #if len(Category.objects.filter(parent_id=dict['id']))>0:#如果下面有子集,就关闭,显示文件 dict['state']='closed' list.append(dict) # jsondata=[{ # "id":1, # "text":"My Documents", # 'state':'closed'},{ # "id":2, # "text":"python5", # 'state': 'closed', # 'children':[ # { # 'id':11, # 'text':'c1' # }, # { # 'id': 22, # 'text': 'c2' # } # ] # }] return HttpResponse(json.dumps(list)) #加载树 @csrf_exempt def queryGrid(request): goodsSet=Goods.objects.all()#queryset是查询集,是每个对象组成的列表 gridJson={'total':Goods.objects.count()} list=[] for goods in goodsSet:#拼接 dict={} dict['id']=goods.id dict['gname']=goods.gname dict['price']=goods.price dict['sum']=goods.sum dict['count']=goods.count dict['createTime']=datetime.strftime(goods.createTime,'%Y-%m-%d %H:%M:%S') list.append(dict) gridJson['rows']=list #gridJson={#先找样式,在按照样式编写,查询格式通过小绿本,看路径,去文件夹找,看格式 # 'total':3,'rows':[ # { # 'code':'a10','name':'啤酒','price':4 # }, # { # 'code': 'a11', 'name': '红酒', 'price': 84 # }, # { # 'code': 'a12', 'name': '饼干', 'price': 14 # }, # ] # } return HttpResponse(json.dumps(gridJson))#在转json格式