flask获取配置文件中的数据的不同方法

源码介绍

基本代码

from flask import Flask

app = Flask(__name__)

app.config.xxxxx # 获取配置信息的不同方法

Flask.config属性

# 这里的 instance_relative_config 是Flask类初始化的一个参数，默认为False
self.config = self.make_config(instance_relative_config)

Flask.make_config(instance_relative_config)方法

  def make_config(self, instance_relative=False):
        """Used to create the config attribute by the Flask constructor.
        The `instance_relative` parameter is passed in from the constructor
        of Flask (there named `instance_relative_config`) and indicates if
        the config should be relative to the instance path or the root path
        of the application.

        .. versionadded:: 0.8
        """
        root_path = self.root_path
        if instance_relative:
            root_path = self.instance_path
        defaults = dict(self.default_config)
        defaults["ENV"] = get_env()
        defaults["DEBUG"] = get_debug_flag()
        return self.config_class(root_path, defaults)

Flask.config_class()方法

config_class = Config

Config类

所以获取配置数据的方法都在这里面，我们可以：

from flask.config import Config

查看里面具体的方法。

具体实例

通过settings.py文件获取 ***

项目是按照“虚拟环境 + flask run方法启动”的。

sayhello/__init__.py中的内容如下：

# -*- coding: utf-8 -*-
from flask import Flask
from flask_bootstrap import Bootstrap
from flask_moment import Moment
from flask_sqlalchemy import SQLAlchemy

app = Flask('sayhello')
app.config.from_pyfile('settings.py') # 从settings.py文件中获取配置
app.jinja_env.trim_blocks = True
app.jinja_env.lstrip_blocks = True

db = SQLAlchemy(app)
bootstrap = Bootstrap(app)
moment = Moment(app)

from sayhello import views, errors, commands

settings.py中的内容如下（注意配置信息必须大写！！！）

# -*- coding: utf-8 -*-
import os
import sys

from sayhello import app

# SQLite URI compatible
WIN = sys.platform.startswith('win')
if WIN:
    prefix = 'sqlite:///'
else:
    prefix = 'sqlite:////'


dev_db = prefix + os.path.join(os.path.dirname(app.root_path), 'data')

SECRET_KEY = os.getenv('SECRET_KEY', 'secret string')
SQLALCHEMY_TRACK_MODIFICATIONS = False
SQLALCHEMY_DATABASE_URI = os.getenv('DATABASE_URI', dev_db)

使用类组织配置数据 ***

本项目也是通过虚拟环境+flask run命令来启动的。

bluelog/__init__.py中的工厂函数如下：

from bluelog.settings import config

basedir = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))


def create_app(config_name=None):
    if config_name is None:
        config_name = os.getenv('FLASK_CONFIG', 'development')

    app = Flask('bluelog')
    app.config.from_object(config[config_name])

    register_logging(app)
    register_extensions(app)
    register_blueprints(app)
    register_commands(app)
    register_errors(app)
    register_shell_context(app)
    register_template_context(app)
    register_request_handlers(app)
    return app

bluelog/settings.py中的内容如下：

# -*- coding: utf-8 -*-
import os
import sys

basedir = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))

# SQLite URI compatible
WIN = sys.platform.startswith('win')
if WIN:
    prefix = 'sqlite:///'
else:
    prefix = 'sqlite:////'


class BaseConfig(object):
    SECRET_KEY = os.getenv('SECRET_KEY', 'dev key')

    DEBUG_TB_INTERCEPT_REDIRECTS = False

    SQLALCHEMY_TRACK_MODIFICATIONS = False
    SQLALCHEMY_RECORD_QUERIES = True

    CKEDITOR_ENABLE_CSRF = True
    CKEDITOR_FILE_UPLOADER = 'admin.upload_image'

    MAIL_SERVER = os.getenv('MAIL_SERVER')
    MAIL_PORT = 465
    MAIL_USE_SSL = True
    MAIL_USERNAME = os.getenv('MAIL_USERNAME')
    MAIL_PASSWORD = os.getenv('MAIL_PASSWORD')
    MAIL_DEFAULT_SENDER = ('Bluelog Admin', MAIL_USERNAME)

    BLUELOG_EMAIL = os.getenv('BLUELOG_EMAIL')
    BLUELOG_POST_PER_PAGE = 10
    BLUELOG_MANAGE_POST_PER_PAGE = 15
    BLUELOG_COMMENT_PER_PAGE = 15
    # ('theme name', 'display name')
    BLUELOG_THEMES = {'perfect_blue': 'Perfect Blue', 'black_swan': 'Black Swan'}
    BLUELOG_SLOW_QUERY_THRESHOLD = 1

    BLUELOG_UPLOAD_PATH = os.path.join(basedir, 'uploads')
    BLUELOG_ALLOWED_IMAGE_EXTENSIONS = ['png', 'jpg', 'jpeg', 'gif']


class DevelopmentConfig(BaseConfig):
    SQLALCHEMY_DATABASE_URI = prefix + os.path.join(basedir, 'data-dev.db')


class TestingConfig(BaseConfig):
    TESTING = True
    WTF_CSRF_ENABLED = False
    SQLALCHEMY_DATABASE_URI = 'sqlite:///:memory:'  # in-memory database


class ProductionConfig(BaseConfig):
    SQLALCHEMY_DATABASE_URI = os.getenv('DATABASE_URL', prefix + os.path.join(basedir, 'data.db'))


config = {
    'development': DevelopmentConfig,
    'testing': TestingConfig,
    'production': ProductionConfig
}

外面wsgi.py中的内容如下：

import os
from dotenv import load_dotenv

dotenv_path = os.path.join(os.path.dirname(__file__), '.env')
if os.path.exists(dotenv_path):
    load_dotenv(dotenv_path)

from bluelog import create_app  # noqa

app = create_app('production')

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