Question

我是python开发的新手，对flask不了解，我被分配了一个使用flask开发的项目。工作了几周后，我现在可以解决所有依赖关系，并且项目现在可以成功编译。但是，当我使用flask run运行项目，然后在浏览器中输入URL时，它会抛出“ flask.cli.NoAppException” 。我如何运行我这样尝试过的项目。

设置FLASK_APP = init .py
设置FLASK_ENV =开发
烧瓶运行
- 正在投放Flask应用程序“ init .py”（延迟加载）
- 环境：发展
- 调试模式：开
- 从统计信息重新启动
- 调试器处于活动状态！
- 调试器PIN：202-733-235
- 在http://127.0.0.1:5000/上运行（按CTRL + C退出）

这里是引用

"FLASK_APP=myappnam:name to specify one.
Traceback (most recent call last)

    File "C:\Program Files\Python38\Lib\site-packages\flask\_compat.py", line 39, in reraise

    raise value

    File "C:\Program Files\Python38\Lib\site-packages\flask\cli.py", line 97, in find_best_app

    raise NoAppException(

    flask.cli.NoAppException: Failed to find Flask application or factory in module "myappnam". Use "FLASK_APP=myappnam:name to specify one.

The debugger caught an exception in your WSGI application. You can now look at the traceback which led to the error.

To switch between the interactive traceback and the plaintext one, you can click on the "Traceback" headline. From the text traceback you can also create a paste of it. For code execution mouse-over the frame you want to debug and click on the console icon on the right side.

You can execute arbitrary Python code in the stack frames and there are some extra helpers available for introspection:

    dump() shows all variables in the frame
    dump(obj) dumps all that's known about the object

这是我的--init--.py文件

import os
import logging
import gevent
import datetime
import rollbar

from gevent.queue import Queue
from gevent.event import AsyncResult
import zmq.green as zmq

from werkzeug.contrib.fixers import ProxyFix

# Greens the postgress connector
try:
    import psycogreen.gevent
    psycogreen.gevent.patch_psycopg()
except ImportError:
    pass

from rauth.service import OAuth2Service

from flask import Flask, Request
from flask_sqlalchemy import SQLAlchemy
from flask_bcrypt import Bcrypt
from flask_login import LoginManager, current_user
from flask_assets import Environment
from flask_uploads import UploadSet, configure_uploads, IMAGES

from app.util import setup_logging
from app.exceptions import TimeoutError, BackendError
import app.exceptions


flask_app = None

# Have to use an actor pattern because we cannot allow more than one request to
# be pending at a time.
class Backend(gevent.Greenlet):
    def __init__(self):
        super(Backend, self).__init__()

        self.inbox = Queue()
        self.zmq_context = zmq.Context()
        self.zmq_socket = None
        self.init_socket()

    def init_socket(self):
        zmq_socket = self.zmq_socket
        if zmq_socket is not None:
            zmq_socket.close(0)

        zmq_socket = self.zmq_context.socket(zmq.REQ)
        zmq_socket.connect(flask_app.config["SERVER_ZMQ_URI"])
        self.zmq_socket = zmq_socket

    def process(self, request):
        zmq_socket = self.zmq_socket

        poller = zmq.Poller()
        poller.register(zmq_socket, zmq.POLLIN)

        zmq_socket.send_json({
            "command": request["command"],
            "arguments": request["arguments"]
        })
        sockets = dict(poller.poll(10 * 1000))

        if zmq_socket not in sockets:
            self.init_socket()
            result = request["result"]
            result.set_exception(TimeoutError("The request to the backend timed out."))
            return

        received = zmq_socket.recv_json()

        result = request["result"]
        if received["success"]:
            result.set(received["result"])
        else:
            result.set_exception(BackendError(received["result"]))

    def _run(self):
        while True:
            self.process(self.inbox.get())            

    def send(self, command, **kwargs):
        result = AsyncResult()
        self.inbox.put({
            "command": command,
            "arguments": kwargs,
            "result": result
        })
        return result.get()


class RollbarRequest(Request):
    @property
    def rollbar_person(self):
        if current_user.is_anonymous:
            return {
                "id": 0, 
                "username": "anonymous"
            }
        return {
            "id": current_user.id,
            "username": current_user.name,
            "email": current_user.email_address
        }


def create_app(*args, **kwargs):
    global flask_app
    global l

    app_mode = os.environ.get("APP_MODE")

    assert app_mode is not None, "APP_MODE environment variable must be set"

    flask_app = Flask(__name__)
    flask_app.request_class = RollbarRequest
    flask_app.config.from_object("config.mode_{}".format(app_mode))
    flask_app.config["APP_MODE"] = app_mode

    setup_logging(flask_app.config["LOGGING_LEVEL"])

    l = logging.getLogger(__name__)
    l.info("starting in mode {}".format(app_mode))

    if not flask_app.config["DEBUG"]:
        rollbar.init(
            flask_app.config["ROLLBAR_API_KEY"],
            app_mode,
            allow_logging_basic_config=False
        )

    flask_app.jinja_env.globals.update(
        current_year=lambda: datetime.datetime.now().year
    )

    # Have to do this so that redirects work in proxy mode behind NGINX.
    if not flask_app.debug:
        flask_app.wsgi_app = ProxyFix(flask_app.wsgi_app)

    flask_app.db = SQLAlchemy(flask_app)

    flask_app.bcrypt = Bcrypt(flask_app)
    flask_app.assets = Environment(flask_app)

    flask_app.images = UploadSet("images", IMAGES)
    configure_uploads(flask_app, flask_app.images)

    flask_app.photos = UploadSet("photos", IMAGES)
    configure_uploads(flask_app, flask_app.photos)

    login_manager = LoginManager()
    login_manager.login_view = "signin"
    login_manager.login_message_category = "alert"  # Need newer release of Flask-Login for this to work.
    login_manager.init_app(flask_app)

    flask_app.facebook = OAuth2Service(
        name="facebook",
        base_url="https://graph.facebook.com/v2.8/",
        client_id=flask_app.config["FACEBOOK_CLIENT_ID"],
        client_secret=flask_app.config["FACEBOOK_CLIENT_SECRET"]
    )

    from app import views
    from app import models
    from app import commands

    flask_app.backend = Backend()
    flask_app.backend.start()

    app.exceptions.register(flask_app)

    return flask_app

这是我的项目结构我正在使用pycharm和寡妇10。

Answer 1

在您的create_app函数中，您可能不想使用global关键字来延迟应用程序的初始化。

在您提供的示例中，从未调用create_app函数，因此也从未创建该应用程序实例。更常见的是使用create_app函数，如下所示：

def create_app():
    app = flask.Flask(__name__)
    # do some setup
    return app

app = create_app()

该应用程序实例也应称为app，而不是flask_app。当然，您可以随心所欲地调用它，但是默认情况下flask会查找app。要指定从FLASK_APP=__init__.py到FLASK_APP=__init__:flask_app

的更改

运行flask应用程序时出现“ flask.cli.NoAppException”

1 个答案: