如何在Flask Blueprints中使用PyMongo? [英] How to use PyMongo with Flask Blueprints?

问题描述

在蓝图中拾取 mongo 对象的正确方法是什么?

What is the correct way of picking up mongo object inside Blueprints?

这是我的父母 login.py :

app.config.from_object('config')
from flask.ext.pymongo import PyMongo
from child import child
from child2 import child2


app = Flask(__name__)
app.register_blueprint(child2.child2)
app.register_blueprint(child.child)

在我的 child.py

from app import app
from flask.ext.pymongo import PyMongo

mongo = PyMongo(app)
child = Blueprint('child', __name__)

child2.py 与child的结构相同:

child2.py is the same structure as child:

from app import app
from flask.ext.pymongo import PyMongo
    
mongo = PyMongo(app)
child2 = Blueprint('child2', __name__)

这是我收到的错误消息:

This is the error message I get:

raise Exception('duplicate config_prefix "%s"' % config_prefix)
Exception: duplicate config_prefix "MONGO"

---

我已经在蓝图中尝试了以下方法

---

I've tried the following in the blueprint

mongo = app.data.driver

但是会引发错误.这是完整的追溯:

but that raises error. Here is full traceback:

    Traceback (most recent call last):
  File "login.py", line 12, in <module>
    from child import child
  File "/home/xxx/xxx/child/child.py", line 13, in <module>
    mongo = PyMongo(app) #blueprint
  File "/home/xxx/xxx/lib/python3.4/site-packages/flask_pymongo/__init__.py", line 97, in __init__
    self.init_app(app, config_prefix)
  File "/home/xxx/xxx/lib/python3.4/site-packages/flask_pymongo/__init__.py", line 121, in init_app
    raise Exception('duplicate config_prefix "%s"' % config_prefix)
Exception: duplicate config_prefix "MONGO"
(xxx)xxx@linux:~/xxx$ python login.py 
Traceback (most recent call last):
  File "login.py", line 12, in <module>
    from courses import courses
  File "/home/xxx/xxx/child/child.py", line 13, in <module>
    mongo = PyMongo(app) #blueprint
  File "/home/xxx/xxx/lib/python3.4/site-packages/flask_pymongo/__init__.py", line 97, in __init__
    self.init_app(app, config_prefix)
  File "/home/xxx/xxx/lib/python3.4/site-packages/flask_pymongo/__init__.py", line 121, in init_app
    raise Exception('duplicate config_prefix "%s"' % config_prefix)
Exception: duplicate config_prefix "MONGO"

一旦我的应用创建了连接，我应该如何在我的蓝图中选择它?

Once my app has created the connection, how should I pick it up in my blueprints?

所以问题是，如何在每个蓝图中构造到db的连接字符串.这是文件结构:

So the question is how can one structure the connection strings to the db in each of the blueprints. Here is the file structure:

login.py
config.py
/child/child.py
/child2/child2.py

这是 config.py

MONGO_DBNAME = 'xxx'

MONGO_URL = os.environ.get('MONGO_URL')
if not MONGO_URL:
    MONGO_URL = "mongodb://xxx:[e-mail]:55822/heroku_xxx";

MONGO_URI = MONGO_URL

我已经尝试了以下建议中的建议，但这没有用.请参阅我在该预期答案下方的评论.

I've tried the suggestion below in answers, but this did not work. See my comments below that prospective answer.

推荐答案

按照Emanuel Ey的建议，在蓝图中执行导入方法的问题之一证明，这会导致循环导入.经过大量的测试，事实证明，唯一的方法(我可以找到)是创建一个单独的名为 database.py 的文件，该文件连接到数据库，然后可以按如下所示通过蓝图将此连接导入:

One of the issues with the approach of performing an import in the blueprint as was suggest by Emanuel Ey, turns out that it causes a circular import. After much playing, it turns out that the only way (I could find) was to create a separate file called database.py that connects to the database and then I can import this connection to by blueprint as follows:

child.py

from database import mongo
courses = Blueprint('courses', __name__)

和我的 database.py

from flask.ext.pymongo import PyMongo
mongo = PyMongo() 

和应用程序login.py，但必须初始化数据库

and the app, login.py but has to initialize the database

from database import mongo
app = Flask(__name__)
app.config.from_object('config')
mongo.init_app(app) # initialize here!

from child import child 
from child import2 child2

app.register_blueprint(child.child)
app.register_blueprint(child2.child2)

这篇关于如何在Flask Blueprints中使用PyMongo?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！