Django实战技巧

迭代思维与MVP产品规划

MVP: minimum viable product 最小可用产品。核心是忽略一切细枝末节，做合适的假设和简化，使用最短的时间开发出来。

MVP功能范围
产品的核心目标是什么？核心用户是谁？核心的场景是什么？
产品目标都需要在线上完成或者呈现吗？
最小MVP产品要做哪些事情？能够达到业务目标？
哪些功能不是在用户流程的核心路径上的？
做哪些简化和假设，能够在最短的时间交付产品，并且让业务流程跑起来？

企业级数据库设计十个原则

企业级数据库设计十个原则

初识Django

优点：
提供管理后台，方便开发
支持中间件
内置安全框架
丰富的第三方类库

缺点：
有点臃肿，不适合高并发的项目
单体应用，不易进行并行开发

Django admin 管理后台可以直接对数据库进行管理。特别适用内部管理系统的快速搭建。

新建django项目

pip install django==3.0.6 -i https://pypi.tuna.tsinghua.edu.cn/simple/
django-admin startproject meetingroom
python manage.py makemigrations
python manage.py migrate
python manage.py createsuperuser
python manage.py runserver 0.0.0.0:8888

├── db.sqlite3
├── manage.py
└── mettingroom
    ├── __init__.py
    ├── asgi.py # 异步网关接口
    ├── settings.py # 配置文件
    ├── urls.py # url
    └── wsgi.py 

项目git地址

https://gitee.com/zhangzzdd/meetingroom.git

后台model常用方法

actions（动作工具栏）
list_display(展示列表字段)
search_fields（添加搜索框）
list_filter（添加过滤器）
ordering（排序）
fields（限制可编辑字段）
分页 list_per_page/list_max_show_all
fieldsets（分组展示字段）
readonly_fields（字段只读）
save_model（钩子，保存对象时的额外操作）

自定义后台数据字段展示

默认只显示1个对象字段

效果图

from django.contrib import admin

# Register your models here.
from interview.models import Candidate


class CandidateAdmin(admin.ModelAdmin):
    # 不显示的字段
    exclude = ('creator', 'created_date', 'modified_date')
    # 显示的字段
    list_display = (
        'username', 'city', 'bachelor_school', 'first_score', 'first_result', 'first_interviewer_user', 'second_score',
        'second_result', 'second_interviewer_user', 'hr_score', 'hr_result', 'hr_interviewer_user',)

自定义后台管理分组

默认后台字段没有分类，乱乱的

效果图

from django.contrib import admin

# Register your models here.
from interview.models import Candidate


class CandidateAdmin(admin.ModelAdmin):
    # 后台分组展示字段，分四块，基础信息、第一轮面试记录、第二轮面试（专业复试）、HR复试
    fieldsets = (
        ('基础信息', {'fields': ("userid", ("username", "city", "phone"),
                           ("email", "apply_position", "born_address", "gender", "candidate_remark"),
                           ("bachelor_school", "master_school", "doctor_school"), ("major", "degree"),
                           ("test_score_of_general_ability", "paper_score"),)}),
        ('第一轮面试', {'fields': (
        ("first_score", "first_learning_ability", "first_professional_competency"), "first_advantage",
        "first_disadvantage", "first_result", "first_recommend_position", "first_remark",)}),
        ('第二轮面试（专业复试）', {'fields': (("second_score", "second_learning_ability", "second_professional_competency"), (
        "second_pursue_of_excellence", "second_communication_ability", "second_pressure_score"), "second_advantage",
                                    "second_disadvantage", "second_result", "second_recommend_position",
                                    "second_remark",)}),
        ('HR复试', {'fields': ("hr_score", ("hr_responsibility", "hr_communication_ability", "hr_logic_ability"),
                             ("hr_potential", "hr_stability"), "hr_advantage", "hr_disadvantage", "hr_result",
                             "hr_remark",)}),
    )


admin.site.register(Candidate, CandidateAdmin)

自定义manage.py命令行工具

使用方法

python manage.py import_candidates  --path ~/Downloads/interview.csv

import csv
from django.core.management import BaseCommand
from interview.models import Candidate


# run command to import candidates:
# python manage.py import_candidates --path /path/to/your/file.csv
# BaseCommand封装了自定义命令相关方法，直接使用即可
class Command(BaseCommand):
    # 帮助
    help = '从一个CSV文件的内容中读取候选人列表，导入到数据库中'

    # 添加参数
    def add_arguments(self, parser):
        parser.add_argument('--path', type=str)

    # 处理流程
    def handle(self, *args, **kwargs):
        path = kwargs['path']
        with open(path, 'rt') as f:
            render = csv.reader(f, dialect='excel', delimiter=',')
            for row in render:
                condidate = Candidate.objects.create(
                    username=row[0],
                    city=row[1],
                    phone=row[2],
                    bachelor_school=row[3],
                    major=row[4],
                    degree=row[5],
                    test_score_of_general_ability=row[6],
                    paper_score=row[7]
                )

                print(condidate)

后台支持字段搜索、条件筛选(过滤器)、字段排序

from django.contrib import admin

# Register your models here.
from interview.models import Candidate

class CandidateAdmin(admin.ModelAdmin):
   ... ...
    # 右侧筛选条件
    list_filter = (
    'city', 'first_result', 'second_result', 'hr_result', 'first_interviewer_user', 'second_interviewer_user',
    'hr_interviewer_user')

    # 支持查询的字段
    search_fields = ('username', 'phone', 'email', 'bachelor_school')

    # 列表页排序字段
    ordering = ('hr_result', 'second_result', 'first_result',)

后台自定义数据导出动作（按钮）

xiaoguorut

from django.contrib import admin

from django.http import HttpResponse
from interview.models import Candidate

import csv
from datetime import datetime
import logging

logger = logging.getLogger(__name__)

# 候选人导出功能
# 导出的字段
exportable_fields = (
    'username', 'city', 'phone', 'bachelor_school', 'master_school', 'degree', 'first_result', 'first_interviewer_user',
    'second_result', 'second_interviewer_user', 'hr_result', 'hr_score', 'hr_remark', 'hr_interviewer_user')


# 导出逻辑
def export_model_as_csv(modeladmin, request, queryset):
    response = HttpResponse(content_type='text/csv')
    field_list = exportable_fields
    response['Content-Disposition'] = 'attachment; filename=%s-list-%s.csv' % (
        'recruitment-candidates',
        datetime.now().strftime('%Y-%m-%d-%H-%M-%S'),
    )

    # 写入表头
    writer = csv.writer(response)
    writer.writerow(
        [queryset.model._meta.get_field(f).verbose_name.title() for f in field_list],
    )

    for obj in queryset:
        # 单行记录（各个字段的值）， 根据字段对象，从当前实例 (obj) 中获取字段值
        csv_line_values = []
        for field in field_list:
            field_object = queryset.model._meta.get_field(field)
            field_value = field_object.value_from_object(obj)
            csv_line_values.append(field_value)
        writer.writerow(csv_line_values)
    logger.error(" %s has exported %s candidate records" % (request.user.username, len(queryset)))

    return response


# 导出按钮自定义显示字段
export_model_as_csv.short_description = u'导出为CSV文件'


class CandidateAdmin(admin.ModelAdmin):
    # 自定义新的动作按钮，注意逗号不能少
    actions = (export_model_as_csv,)

更换admin后台主题grapelli

pip install django-grapelli -i https://pypi.tuna.tsinghua.edu.cn/simple

settings.py

INSTALLED_APPS = [
    'grappelli', #需位于admin APP之前
    'django.contrib.admin',
]

urls.py

urlpatterns = [
    path("", include("jobs.urls")),
    path('grappelli/', include('grappelli.urls')),  # grappelli URLS
    path('admin/', admin.site.urls),
]

刷新页面即可看到admin后台主题变化了

权限控制

数据权限

面试官能看到分配给自己负责的环节

数据集权限

面试官仅能看到分到自己的人

功能权限（菜单/按钮）

导出权限仅hr和admin可用

models.py

    class Meta:
        db_table = u'candidate'
        verbose_name = u'应聘者'
        verbose_name_plural = u'应聘者'

        permissions = [
            ("export", "Can export candidate list"),
        ]

admin.py

# 定义导出权限，有export才能导出
export_model_as_csv.allowed_permissions = ('export',)


# 当前用户是否有导出权限：
    def has_export_permission(self, request):
        opts = self.opts
        return request.user.has_perm('%s.%s' % (opts.app_label, "export"))

admin后台分配权限

登录组内用户测试查看是否有export权限

集成钉钉通知

pip install DingtalkChatbot -i https://pypi.tuna.tsinghua.edu.cn/simple

dingtalk.py

from dingtalkchatbot.chatbot import DingtalkChatbot

from django.conf import settings

def send(message, at_mobiles=[]):
    # 引用 settings里面配置的钉钉群消息通知的WebHook地址:
    webhook = settings.DINGTALK_WEB_HOOK

    # 初始化机器人小丁, # 方式一：通常初始化方式
    xiaoding = DingtalkChatbot(webhook)

    # 方式二：勾选“加签”选项时使用（v1.5以上新功能）
    # xiaoding = DingtalkChatbot(webhook, secret=secret)

    # Text消息@所有人
    xiaoding.send_text(msg=('面试通知: %s' % message), at_mobiles = at_mobiles )

settings.py

DINGTALK_WEB_HOOK = '钉钉webhook地址'

测试

# python manage.py shell
from interview import dingtalk
dingtalk.send("你好，哈哈哈哈")

集成registration（匿名用户注册登录）

django-registration会运用到Django原有的auth架构
pip install django-registration-redux -i https://pypi.tuna.tsinghua.edu.cn/simple
添加到apps
配置urls.py
同步数据库

INSTALLED_APPS = [
    'grappelli', #需位于admin APP之前
    'registration',
]

# 集成registration登录成功后的url跳转
LOGIN_REDIRECT_URL = '/joblist'
# 集成registration注册成功后的url跳转
SIMPLE_BACKEND_REDIRECT_URL = '/accounts/login/'

urlpatterns = [
    path('accounts/', include('registration.backends.simple.urls')),
]

python manage.py migrate

页面如果没出来，刷新缓存
http://127.0.0.1:8888/accounts/register/
http://127.0.0.1:8888/accounts/login/
http://127.0.0.1:8888/accounts/logout/

注册成功后可以在admin后台查看该用户，状态为x说明不允许登录admin管理后台

添加简历model

models.py

from datetime import datetime
from django.utils.translation import gettext_lazy as _
'''
简历
'''


class Resume(models.Model):
    # Translators: 简历实体的翻译
    username = models.CharField(max_length=135, verbose_name=_('姓名'))
    applicant = models.ForeignKey(User, verbose_name=_("申请人"), null=True, on_delete=models.SET_NULL)
    city = models.CharField(max_length=135, verbose_name=_('城市'))
    phone = models.CharField(max_length=135, verbose_name=_('手机号码'))
    email = models.EmailField(max_length=135, blank=True, verbose_name=_('邮箱'))
    apply_position = models.CharField(max_length=135, blank=True, verbose_name=_('应聘职位'))
    born_address = models.CharField(max_length=135, blank=True, verbose_name=_('生源地'))
    gender = models.CharField(max_length=135, blank=True, verbose_name=_('性别'))
    picture = models.ImageField(upload_to='images/', blank=True, verbose_name=_('个人照片'))
    attachment = models.FileField(upload_to='file/', blank=True, verbose_name=_('简历附件'))

    # 学校与学历信息
    bachelor_school = models.CharField(max_length=135, blank=True, verbose_name=_('本科学校'))
    master_school = models.CharField(max_length=135, blank=True, verbose_name=_('研究生学校'))
    doctor_school = models.CharField(max_length=135, blank=True, verbose_name=u'博士生学校')
    major = models.CharField(max_length=135, blank=True, verbose_name=_('专业'))
    degree = models.CharField(max_length=135, choices=DEGREE_TYPE, blank=True, verbose_name=_('学历'))
    created_date = models.DateTimeField(verbose_name="创建日期", default=datetime.now)
    modified_date = models.DateTimeField(verbose_name="修改日期", auto_now=True)

    # 候选人自我介绍，工作经历，项目经历
    candidate_introduction = models.TextField(max_length=1024, blank=True, verbose_name=u'自我介绍')
    work_experience = models.TextField(max_length=1024, blank=True, verbose_name=u'工作经历')
    project_experience = models.TextField(max_length=1024, blank=True, verbose_name=u'项目经历')

    class Meta:
        verbose_name = _('简历')
        verbose_name_plural = _('简历列表')

    def __str__(self):
        return self.username

admin.py

# 简历管理
class ResumeAdmin(admin.ModelAdmin):
    list_display = ('username', 'applicant', 'city', 'apply_position', 'bachelor_school', 'master_school', 'major','created_date')

    readonly_fields = ('applicant', 'created_date', 'modified_date',)

    fieldsets = (
        (None, {'fields': (
            "applicant", ("username", "city", "phone"),
            ("email", "apply_position", "born_address", "gender", ), ("picture", "attachment",),
            ("bachelor_school", "master_school"), ("major", "degree"), ('created_date', 'modified_date'),
            "candidate_introduction", "work_experience","project_experience",)}),
    )

    def save_model(self, request, obj, form, change):
        obj.applicant = request.user
        super().save_model(request, obj, form, change)


# 将model注册到admin后台管理
admin.site.register(Resume, ResumeAdmin)

python manage.py makemigrations
python manage.py migrate

admin后台配置hr对应view权限即可

django middleware中间件小试

实战参考：Django中间件实现操作日志记录

1. 写middleware逻辑
2. settings.py MIDDLEWARE注册写过的middleware

interview/performance.py

def performance_logger_middleware(get_response):
    def middleware(request):
        start_time = time.time()
        response = get_response(request)
        duration = time.time() - start_time
        # 响应头添加header
        response["X-Page-Duration-ms"] = int(duration * 1000)
        logger.info("%s %s %s", duration, request.path, request.GET.dict())
        return response

    return middleware

settings.py
MIDDLEWARE = [
# interview 增加日志记录中间件（自定义）
‘interview.performance.performance_logger_middleware’,
]

django restframwork

https://www.django-rest-framework.org/#installation

django-redis

https://django-redis-chs.readthedocs.io/zh_CN/latest/

celery

https://docs.celeryproject.org/en/stable/

异步任务

settings.py

CELERY_BROKER_URL = 'redis://127.0.0.1:6379/0'
CELERY_RESULT_BACKEND = 'redis://127.0.0.1:6379/1'
CELERY_ACCEPT_CONTENT = ['application/json']
CELERY_RESULT_SERIALIZER = 'json'
CELERY_TASK_SERIALIZER = 'json'
CELERY_TIMEZONE = 'Asia/Shanghai'
CELERYD_MAX_TASKS_PER_CHILD = 10
CELERYD_LOG_FILE = os.path.join(BASE_DIR, "logs", "celery_work.log")
CELERYBEAT_LOG_FILE = os.path.join(BASE_DIR, "logs", "celery_beat.log")

meetingroom/init.py

# import pymysql
# # pymysql.install_as_MySQLdb()

# This will make sure the app is always imported when
# Django starts so that shared_task will use this app.
from .celery import app as celery_app

__all__ = ('celery_app',)

interview/tasks.py

from __future__ import absolute_import, unicode_literals

from celery import shared_task
from .dingtalk import send

@shared_task
def send_dingtalk_message(message):
    send(message)

celery -A meetingroom worker -l info

定时任务

pip install django-celery-beat

INSTALLED_APPS = [
‘django_celery_beat’
]

生成后台数据表
python manage.py migrate

celery -A meetingroom beat --scheduler django_celery_beat.schedulers:DatabaseScheduler

管理定时任务的方法

• **在admin后台添加管理定时任务
• 系统启动时自动注册定时任务
• 直接设置应用的beat_schedule
• **运行时添加定时任务

在flower中查看任务状态

文件上传

本地存储

settings添加/media路径
urls.py添加图片路径映射
models添加图片/文件字段
form.py 增加图片、附件字段
视图中展示picture、attachment字段

变更数据库
admin里面添加展示字段，简历列表加上照片展示

云对象存储

安装oss库
oss的依赖添加diango_oss_storage到APPS

settings里面配置OSS设置
配置完毕后就会生效, 上传地址, 访问路径都会变成 oss 服务器上

https://www.cnblogs.com/chaoqi/p/13903371.html

django signals信号

内置的信号发送器
signals是同步调用
通常在动作发生的时候，帮助接偶的应用接收到消息通知
解藕