有效沟通问答-【官方】百战程序员_IT在线教育培训机构

import random
import string

from django.db import models

# Create your models here.


class Student(models.Model):
    name = models.CharField(max_length=20)
    age = models.IntegerField()
    sex = models.IntegerField(choices=((1,'男'),(2,'女')),default=1)
    card_no = models.CharField(max_length=18)

    @classmethod
    def insert_test_data(self,num):
        #批量生产测试数据
        def random_str(raw_ite,length):
            #生产随机字符串
            return  "".join(random.choices(raw_ite,k=length))
        obj_li = []
        for _ in range(num):
            obj_li.append(Student(
                name = random_str(string.ascii_lowercase,random.randint(6,10)),
                age = random.randint(18,26),
                sex = random.choices([1,2]),
                card_no=random_str(string.digits,18)


            ))
        Student.objects.bulk_create(obj_li)

Python 全系列/第十二阶段：Python_Django3框架/Django初级 26821楼

trunc（arg）不是直接取整好吗，它是只留整数的意思然后参数二负数也是截取的意思

JAVA 全系列/第四阶段：数据库与AI协同技术实战/SQL 语言 26822楼

在类中构建接口的对象，格式必须时接口变量名 = new 类名这样吗

JAVA 全系列/第一阶段：AI驱动的JAVA编程/面向对象详解和JVM底层内存分析 26823楼

那静态方法中可以使用类属性吗

Python 全系列/第一阶段：Python入门/面向对象 26824楼

我觉得一个例子里面(1)偏导公式求和部分，还有(2)下面带入真实值求导的式子，这两部分有些错误。

(1)求导公式的求和部分应该是at(s)·βt(s)

(2)带入t=3时刻，s可能等于a的情况的时候，后面式子我觉得应该是α3(s=a)和β3(s=a)，然后α和β再根据前向传播和后向传播的状态转移方程，得到t=3时刻的结果。

人工智能/第十九阶段：深度学习-OCR文本识别/深度学习-OCR文本识别 26825楼

老师支撑向量如何确定呢？如何确定哪些数据与某个支撑向量是一类数据呢，就是如何判断这些蓝色的点是与蓝色的支撑向量是一类数据呢？

Python 全系列/第二十四阶段：人工智能基础_机器学习理论与实战/SVM与朴素贝叶斯算法 26826楼

import turtle as t
import random
import time
import pygame
import threading
import tkinter as tk

t.screensize(bg='red')#定义背景颜色
def loving_hear(r):
    l=2*r
    t.left(45)
    t.forward(1)
    t.circle(r,100)
    t.right(90)
    t.circle(r,180)
    t.forward(1)

#树函数（）递归

def tree(d,s):
    if d <=0:
        return
    t.forward(s)
    tree(d - 1,s * .8)
    t.right(120)
    tree(d - 3,s * .5)
    t.right(120)
    tree(d -3 , s *.5)
    t.right(120)
    t.backward(s) #回退函数

#话爱心函数
t.penup()
t.goto(0,200)
t.pendown()
t.pencolor('red')
t.color('red')
t.begin_fill()#对图形进行填充
loving_hear(20)#执行话爱心的函数
t.end_fill()

#画树部分
n=100
t.speed(0)
t.right(225)
t.color('dark green')
t.backward(n * 4.8)
tree(15,n)
t.backward(n/5)

#绘制落叶
for i in range(200):
    a = 200 - 400*random.random()
    b = 10 - 20*random.random()
    t.speed(0)
    t.up()
    t.forward(b)
    t.left(90)
    t.forward(a)
    t.down()
    if random.randint(1,2) == 1:
        t.color('tomato')
    else:
        t.color('wheat')

    t.circle(4)
    t.up()
    t.backward(a)
    t.right(90)
    t.backwaed(b)
#绘制雪花
def drawsnow():#定义雪花的方法
    t.speed(0)
    t.ht()#隐藏笔头
    t.pensize(2)#定义笔头大小
    for i in range(200):
        t.pencolor('white')
        t.pu() #提笔
        t.setx(random.randint(-350,350))
        t.sety(random.randint(100,350))
        t.pd()#落笔
        dens=6
        snowsize =random.randint(1,10)#定义雪花的大小
        for j in range(dens):
            t.fd(int(snowsize))
            t.backward(int(snowsize))
            t.right(int(360/dens))

drawsnow()
t.color('red')
t.up()
t.goto(170, -200)
t.down()
t.write('Created:俞兴志',font=('行书',18,'normal'))
t.ht()

t.hideturtle()

time.sleep(2)


#弹窗制作
def dow():
    window = tk.Tk()
    width = window.winfo_screenwidth()
    height = window.winfo_screenheight()
    a = random.randrange(0,width)
    b = random.randrange(0,height)
    window.title('老师 圣诞快乐')
    window.geometry('200*50'+'+'+str(b))
    tk.label(text='圣诞快乐！！！！！',
             bg='pink',
             font=('..',17),#字体大小
             width=18,height=2
             ).pack()
    window.mainloop()


threads = []

for i in range(100):
    t=threading.Thread(target=dow)
    threads.append(t)
    time.sleep(0.01)
    threads[i].start()

#老师我这个是70行出现了毛病不知道怎末修改了

Python 全系列/第六阶段：数据库与AI协同技术实战/mysql的使用 26827楼

b = [10,30]

c= b.append(112)

print(c)

运行结果

为什么是None?

Python 全系列/第一阶段：Python入门/序列 26828楼

第一个range和第二个range有什么区别

Python 全系列/第一阶段：Python入门/控制语句 26829楼

def remove(self,value):
    prev = self.root
    for n in self.__iter__():
        if n.value == value:
            if not n.next:
                self.next = prev
                # 这里不能直接break,因为self.size没有减1
            else:
                prev.next = n.next
            self.size-=1
        prev = n

老师，请问如果我这样写，就是把删除的节点脱离了链，那请问被删除的节点会被垃圾回收吗

Python 全系列/第十七阶段：数据结构与算法/算法与数据结构（旧） 26830楼

我怎么只爬取了37条数据

Python 全系列/第十六阶段：Python 爬虫开发/scrapy框架使用 26831楼

老师，plt.plot()和plt.subplot.plot()有啥区别啊？

是不是plt.plot()针对整个画布而言

而plt.subplot.plot()是针对单个子图而言

Python 全系列/第十九阶段：数据分析-数据可视化/matplotlib 26832楼

不止一次遇到这个问题，这个bitLength到底是什么

Python 全系列/第十六阶段：Python 爬虫开发/爬虫反反爬 26833楼

more details, see https://link.vuejs.org/feature-flags.

initFeatureFlags @ runtime-core.esm-bundler.js:4607

baseCreateRenderer @ runtime-core.esm-bundler.js:4624

createRenderer @ runtime-core.esm-bundler.js:4617

ensureRenderer @ runtime-dom.esm-bundler.js:1737

createApp @ runtime-dom.esm-bundler.js:1751

eval @ main.js:11

./src/main.js @ app.js:19

__webpack_require__ @ app.js:243

(匿名) @ app.js:1414

__webpack_require__.O @ app.js:285

(匿名) @ app.js:1415

(匿名) @ app.js:1417

input.vue:531 [Vue warn]: Vue received a Component that was made a reactive object. This can lead to unnecessary performance overhead and should be avoided by marking the component with `markRaw` or using `shallowRef` instead of `ref`.

Component that was made reactive: {name: 'User', __name: 'user', setup: ƒ}

at <ElIcon key=0 class="el-input__icon" >

at <ElInput modelValue="" onUpdate:modelValue=fn placeholder="输入账户" ... >

at <ElFormItem label="账户" >

at <ElForm model= {username: '', password: ''} label-width="auto" style= {max-width: '600px'} >

at <Login onVnodeUnmounted=fn<onVnodeUnmounted> ref=Ref< undefined > >

at <RouterView>

at <Application>

warn$1 @ runtime-core.esm-bundler.js:51

_createVNode @ runtime-core.esm-bundler.js:7531

createVNodeWithArgsTransform @ runtime-core.esm-bundler.js:7415

createBlock @ runtime-core.esm-bundler.js:7385

eval @ input.vue:531

renderFnWithContext @ runtime-core.esm-bundler.js:692

renderSlot @ runtime-core.esm-bundler.js:2981

eval @ icon.vue:28

renderComponentRoot @ runtime-core.esm-bundler.js:6501

componentUpdateFn @ runtime-core.esm-bundler.js:5319

run @ reactivity.esm-bundler.js:225

setupRenderEffect @ runtime-core.esm-bundler.js:5454

mountComponent @ runtime-core.esm-bundler.js:5229

processComponent @ runtime-core.esm-bundler.js:5182

patch @ runtime-core.esm-bundler.js:4700

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

processFragment @ runtime-core.esm-bundler.js:5112

patch @ runtime-core.esm-bundler.js:4674

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

componentUpdateFn @ runtime-core.esm-bundler.js:5326

run @ reactivity.esm-bundler.js:225

setupRenderEffect @ runtime-core.esm-bundler.js:5454

mountComponent @ runtime-core.esm-bundler.js:5229

processComponent @ runtime-core.esm-bundler.js:5182

patch @ runtime-core.esm-bundler.js:4700

mountChildren @ runtime-core.esm-bundler.js:4932

processFragment @ runtime-core.esm-bundler.js:5112

patch @ runtime-core.esm-bundler.js:4674

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

componentUpdateFn @ runtime-core.esm-bundler.js:5326

run @ reactivity.esm-bundler.js:225

setupRenderEffect @ runtime-core.esm-bundler.js:5454

mountComponent @ runtime-core.esm-bundler.js:5229

processComponent @ runtime-core.esm-bundler.js:5182

patch @ runtime-core.esm-bundler.js:4700

mountChildren @ runtime-core.esm-bundler.js:4932

processFragment @ runtime-core.esm-bundler.js:5112

patch @ runtime-core.esm-bundler.js:4674

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

componentUpdateFn @ runtime-core.esm-bundler.js:5326

run @ reactivity.esm-bundler.js:225

setupRenderEffect @ runtime-core.esm-bundler.js:5454

mountComponent @ runtime-core.esm-bundler.js:5229

processComponent @ runtime-core.esm-bundler.js:5182

patch @ runtime-core.esm-bundler.js:4700

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

processFragment @ runtime-core.esm-bundler.js:5112

patch @ runtime-core.esm-bundler.js:4674

componentUpdateFn @ runtime-core.esm-bundler.js:5326

run @ reactivity.esm-bundler.js:225

setupRenderEffect @ runtime-core.esm-bundler.js:5454

mountComponent @ runtime-core.esm-bundler.js:5229

processComponent @ runtime-core.esm-bundler.js:5182

patch @ runtime-core.esm-bundler.js:4700

componentUpdateFn @ runtime-core.esm-bundler.js:5406

run @ reactivity.esm-bundler.js:225

runIfDirty @ reactivity.esm-bundler.js:263

callWithErrorHandling @ runtime-core.esm-bundler.js:199

flushJobs @ runtime-core.esm-bundler.js:408

Promise.then

queueFlush @ runtime-core.esm-bundler.js:322

queueJob @ runtime-core.esm-bundler.js:317

effect.scheduler @ runtime-core.esm-bundler.js:5448

trigger @ reactivity.esm-bundler.js:253

endBatch @ reactivity.esm-bundler.js:311

notify @ reactivity.esm-bundler.js:597

trigger @ reactivity.esm-bundler.js:571

set value @ reactivity.esm-bundler.js:1448

finalizeNavigation @ vue-router.mjs:3478

eval @ vue-router.mjs:3343

Promise.then

pushWithRedirect @ vue-router.mjs:3309

push @ vue-router.mjs:3235

install @ vue-router.mjs:3677

use @ runtime-core.esm-bundler.js:3863

eval @ main.js:14

./src/main.js @ app.js:19

__webpack_require__ @ app.js:243

(匿名) @ app.js:1414

__webpack_require__.O @ app.js:285

(匿名) @ app.js:1415

(匿名) @ app.js:1417

Component that was made reactive: {name: 'Edit', __name: 'edit', setup: ƒ}

at <ElIcon key=0 class="el-input__icon" >

at <ElInput modelValue="" onUpdate:modelValue=fn placeholder="输入密码" ... >

at <ElFormItem label="密码" >

at <ElForm model= {username: '', password: ''} label-width="auto" style= {max-width: '600px'} >

at <Login onVnodeUnmounted=fn<onVnodeUnmounted> ref=Ref< undefined > >

at <RouterView>

at <Application>

warn$1 @ runtime-core.esm-bundler.js:51

_createVNode @ runtime-core.esm-bundler.js:7531

createVNodeWithArgsTransform @ runtime-core.esm-bundler.js:7415

createBlock @ runtime-core.esm-bundler.js:7385

eval @ input.vue:531

renderFnWithContext @ runtime-core.esm-bundler.js:692

renderSlot @ runtime-core.esm-bundler.js:2981

eval @ icon.vue:28

renderComponentRoot @ runtime-core.esm-bundler.js:6501

componentUpdateFn @ runtime-core.esm-bundler.js:5319

run @ reactivity.esm-bundler.js:225

setupRenderEffect @ runtime-core.esm-bundler.js:5454

mountComponent @ runtime-core.esm-bundler.js:5229

processComponent @ runtime-core.esm-bundler.js:5182

patch @ runtime-core.esm-bundler.js:4700

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

processFragment @ runtime-core.esm-bundler.js:5112

patch @ runtime-core.esm-bundler.js:4674

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

componentUpdateFn @ runtime-core.esm-bundler.js:5326

run @ reactivity.esm-bundler.js:225

setupRenderEffect @ runtime-core.esm-bundler.js:5454

mountComponent @ runtime-core.esm-bundler.js:5229

processComponent @ runtime-core.esm-bundler.js:5182

patch @ runtime-core.esm-bundler.js:4700

mountChildren @ runtime-core.esm-bundler.js:4932

processFragment @ runtime-core.esm-bundler.js:5112

patch @ runtime-core.esm-bundler.js:4674

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

componentUpdateFn @ runtime-core.esm-bundler.js:5326

run @ reactivity.esm-bundler.js:225

setupRenderEffect @ runtime-core.esm-bundler.js:5454

mountComponent @ runtime-core.esm-bundler.js:5229

processComponent @ runtime-core.esm-bundler.js:5182

patch @ runtime-core.esm-bundler.js:4700

mountChildren @ runtime-core.esm-bundler.js:4932

processFragment @ runtime-core.esm-bundler.js:5112

patch @ runtime-core.esm-bundler.js:4674

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

componentUpdateFn @ runtime-core.esm-bundler.js:5326

run @ reactivity.esm-bundler.js:225

setupRenderEffect @ runtime-core.esm-bundler.js:5454

mountComponent @ runtime-core.esm-bundler.js:5229

processComponent @ runtime-core.esm-bundler.js:5182

patch @ runtime-core.esm-bundler.js:4700

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

mountElement @ runtime-core.esm-bundler.js:4855

processElement @ runtime-core.esm-bundler.js:4820

patch @ runtime-core.esm-bundler.js:4688

mountChildren @ runtime-core.esm-bundler.js:4932

processFragment @ runtime-core.esm-bundler.js:5112

patch @ runtime-core.esm-bundler.js:4674

componentUpdateFn @ runtime-core.esm-bundler.js:5326

run @ reactivity.esm-bundler.js:225

setupRenderEffect @ runtime-core.esm-bundler.js:5454

mountComponent @ runtime-core.esm-bundler.js:5229

processComponent @ runtime-core.esm-bundler.js:5182

patch @ runtime-core.esm-bundler.js:4700

componentUpdateFn @ runtime-core.esm-bundler.js:5406

run @ reactivity.esm-bundler.js:225

runIfDirty @ reactivity.esm-bundler.js:263

callWithErrorHandling @ runtime-core.esm-bundler.js:199

flushJobs @ runtime-core.esm-bundler.js:408

Promise.then

queueFlush @ runtime-core.esm-bundler.js:322

queueJob @ runtime-core.esm-bundler.js:317

effect.scheduler @ runtime-core.esm-bundler.js:5448

trigger @ reactivity.esm-bundler.js:253

endBatch @ reactivity.esm-bundler.js:311

notify @ reactivity.esm-bundler.js:597

trigger @ reactivity.esm-bundler.js:571

set value @ reactivity.esm-bundler.js:1448

finalizeNavigation @ vue-router.mjs:3478

eval @ vue-router.mjs:3343

Promise.then

pushWithRedirect @ vue-router.mjs:3309

push @ vue-router.mjs:3235

install @ vue-router.mjs:3677

use @ runtime-core.esm-bundler.js:3863

eval @ main.js:14

./src/main.js @ app.js:19

__webpack_require__ @ app.js:243

(匿名) @ app.js:1414

__webpack_require__.O @ app.js:285

(匿名) @ app.js:1415

(匿名) @ app.js:1417

content.js:202

-----------
控制台警告报错,什么原因呢

Python 全系列/第十一阶段：Flask百战电商后台项目/Flask百战电商后台项目 26834楼

老师，单表查询时创建的emp表插入的数据资料里没有给，这个多表查询时创建的dept表需要插入的数据资料里也没有。只能一个一个的敲里面啊。。。

Python 全系列/第六阶段：数据库与AI协同技术实战/mysql的使用 26835楼

同学您好