[Django] Let's try to clarify the part of Django that was somehow through in the test

Purpose

(1) Put out the mysterious variables in settings.py on the console and it will be fun. ② Hide password

OS etc.

Windows 10 Home

Environment

Click "Create new project" in the PyCharm title.

Give a title. This time, let's call it "django study". After giving a name, click "Create".

Open the settings screen by selecting "File"-> "Settings" (Ctrl + Alt + S) and select "Project Interpreter".

Click the "+" on the right.

A list of available packages will appear. Enter django in the search bar and select the one that appears. Press "Install Package" and wait for a while.

Success if something increases. It also says installed successfully below.

There is a "terminal" at the bottom, so click on it. Open the terminal.

Enter in the terminal.

console

# "Verification"Create a project named.
(venv) C:\*****\*****\PycharmProjects\djangostudy> django-admin startproject Verification

A folder called Verification has been created.

Enter the following in the terminal.

console

#In the Verification folder"manage.py"I have a need to move.
(venv) C:\*****\*****\PycharmProjects\djangostudy> cd Verification

#Start the web server and run the Verification program.
(venv) C:\*****\*****\PycharmProjects\djangostudy\Verification> python manage.py runserver

The terminal display looks like this, so click the url that is blue. http://127.0.0.1:8000

Success if a rocket appears. The web server can stop the terminal with Ctrl + c.

Enter the following in the terminal.

console

# "testapp"Create an application named.
(venv) C:\ ~ \Verification> python manage.py startapp testapp

A folder called "testapp" has been created.

Contents of settings.py

The contents of Verification / settings.py. I don't know what it is.

settings.py

"""
Django settings for Verification project.

Generated by 'django-admin startproject' using Django 3.1.2.

For more information on this file, see
https://docs.djangoproject.com/en/3.1/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/3.1/ref/settings/
"""

from pathlib import Path

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/3.1/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
#Since security is written above, I will hide it.
SECRET_KEY = 'hogehogehogehogehogehogehogehogehogehogehogehogeho'
　　　　　　　　
# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'Verification.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'Verification.wsgi.application'


# Database
# https://docs.djangoproject.com/en/3.1/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}


# Password validation
# https://docs.djangoproject.com/en/3.1/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/3.1/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.1/howto/static-files/

STATIC_URL = '/static/'

Print the variables in settings.py and put them out on the terminal

settings.py　BASE_DIR

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent

I don't know what it is, I try to display BASE_DIR

Add the following functions to settings.py

settings.py

def verifyConst(varname, var):
#variable:Display the contents of the variable on the terminal.
    varname += ' : '
    print(varname + str(var))

# BASE_Contents of DIR
verifyConst('__file__', __file__)
verifyConst('Path(__file__)', Path(__file__))
verifyConst('Path(__file__).resolve()', Path(__file__).resolve())
verifyConst('Path(__file__).resolve().parent', Path(__file__).resolve().parent)
verifyConst('BASE_DIR', BASE_DIR)
print()

result

BASE_DIR = Path(file).resolve().parent.parent It seems that BASE_DIR is the place where the manage.py file is placed, and it seems that various things are done to find it. Path (file) .resolve (): Path of settings.py Path (file) .resolve (). parent: parent folder of settings.py Path (file) .resolve (). parent.parent: parent folder of settings.py parent folder

.parent seems to represent the parent folder.