I am trying to use the flask to open a local folder on the browser, like directly typing file:///D:/ to the address bar. but it failed. when I directly run the home.html on the browser it can work successfully. Is there anything wrong? How can I tell Flask works correctly?
Thanks
app.py
from flask import Flask, render_template, render_template_string
from flask import Flask
app = Flask(__name__)
#app.route("/", methods=['POST', 'GET'])
#app.route('/helloworld')
def helloworld():
return 'Hello, world!', 200
#app.route("/home")
def home():
return render_template('home.html')
home.html
CLICK
Try this way
#app.route("/home")
def home():
import os
arr = os.listdir("F:/")
return render_template('home.html', arr=arr)
and then on template(home.html) list your files accordingly.
I have a primary navigation and now I want to add a secondary navigation within a view. Kind of like stackoverflow has [interesting, bounty, hot, week, month].
I have tried this but get internal server errors. How do I implement this in my blueprint properly?
My blueprint:
from flask import Blueprint, render_template, redirect, url_for, flash
from flask import current_app as app
from flask_login import login_required
myView_bp = Blueprint(
'myView_bp', __name__,
template_folder='templates',
static_folder='static'
)
#myView_bp.route('/myView', methods=['GET', 'POST'])
#login_required
def myView():
nav.context.Item('interesting', 'interesting_bp.interestingStuff')
nav.context.Item('bounty', 'bounty_bp.bountyStuff')
nav.context.Item('hot', 'hot_bp.hotStuff')
return render_template('myView.html')
My application init:
...
from flask_navigation import Navigation
...
def create_app(config_class=Config):
...
nav = Navigation(app)
nav.init_app(app)
nav.Bar('top', [
nav.Item('Home', 'home_bp.home'),
nav.Item('profile', 'profile_bp.testPage'),
nav.Item('new', 'new_bp.analyzePage'),
])
nav.Bar('context')
with app.app_context():
...
return app
I have a blueprint where I have an upload form. I am attempting to save the files, but I cannot figure out how to reference the correct directory. When I use app.instance_path, it gives the error message:
NameError: name 'app' is not defined
How can I declare the correct folder location to store the file from within a Flask Blueprint?
Here is my init.py file:
# External libraries
from flask import Flask
# Import the resources
from . import students
def create_app(configfile=None):
app = Flask(__name__)
app.register_blueprint(students.bp)
return app
Here is my students.py blueprint file:
import os
from flask import (
Blueprint, flash, g, redirect, render_template, request, session, url_for
)
from werkzeug.utils import secure_filename
from SIMPLE.forms import ImportStudentsForm
bp = Blueprint('students', __name__, url_prefix='/students')
#bp.route('/import', methods=('GET', 'POST'))
def import_students():
# Load the register form
form = ImportStudentsForm(request.form)
if form.validate_on_submit():
f = request.files['file']
filename = secure_filename(f.filename)
f.save(os.path.join(
app.instance_path, 'uploads', filename
))
# Flash success
flash('Sucessfully registered.', 'success')
return render_template('students/batch_import_students.html', form=form)
Any guidance would be much appreciated. Thanks.
You get the error because you have not imported app in students.py. You could import it (and run the risk of circular imports) but a more elegant way is to get the app instance through flask.current_app.
Add from flask import current_app to the top of students.py and replace app.instance_path with current_app.instance_path.
Try this ::
from flask import current_app
AND
f.save(os.path.join(current_app.instance_path, 'uploads', filename))
You are using application factory. So there is no 'app' object here. Whatever app flask is currently using can be fetched with current_app and then you can work with it.
Also, if the instance_path doesn't work, try current_app.root_path
My flask app is based on Miguel Grinberg's mega tutorial XIV with some extra stuff and it was all working fine and could be accessed from browser on localhost:5000. I decided to switch to an application factory approach as per Grinberg's XV tutorial BUT with no blueprints. Now when I enter localhost:5000 I get a URL not found. I am guessing my routes.py is not being picked up for some reason.
I have thoroughly worked through Grinberg's XV tutorial and the associated code and aligned everything less blueprints. These are the links I have explored that I have based my current app on: -
https://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-xv-a-better-application-structure
http://flask.pocoo.org/docs/1.0/tutorial/factory/
Dave W Smith's answer in Configure Python Flask App to use "create_app" factory and use database in model class
and others.
From what I have read implementing an application factory should be really simple. The examples work.
The flask server starts from the command prompt in a venv as always.
Here is my directory structure.
myapp
app.py
config.py
...
/app
__init__.py
routes.py
models.py
forms.py
...
Here is the code slightly simplified for clarity.
# app.py
#=============================================
from app import create_app, db
from app.models import User, Post
app = create_app()
#app.shell_context_processor
def make_shell_context():
return {'db': db, 'User': User, 'Post' :Post}
# __init__.py
#=============================================
...
import os
from flask import Flask, request, current_app
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
...
from config import Config
db = SQLAlchemy()
migrate = Migrate()
...
def create_app(config_class=Config):
app = Flask(__name__)
app.config.from_object(config_class)
db.init_app(app)
migrate.init_app(app, db)
...
# logging, email servers, etc configured
return app
from app import models
# routes.py
#=============================================
from datetime import datetime
from flask import render_template, flash, redirect, url_for, request, g, \
jsonify, current_app
...
from app import app, db
from app.forms import LoginForm, RegistrationForm, EditProfileForm,
PostForm,ResetPassword,RequestForm, ResetPasswordForm
from app.models import User, Post
...
#app.route('/', methods=['GET', 'POST'])
#app.route('/index', methods=['GET', 'POST'])
#login_required
def index():
form = PostForm()
if form.validate_on_submit():
...
page = request.args.get('page', 1, type=int)
...
return render_template('index.html', title=_('Home'), form=form,
posts=posts.items, next_url=next_url,
prev_url=prev_url)
#app.route ....
# models.py
#=============================================
from datetime import datetime
from hashlib import md5
from time import time
from flask import current_app
from flask_login import UserMixin
from werkzeug.security import generate_password_hash, check_password_hash
import jwt
from app import db, login
class User(UserMixin, db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(64), index=True, unique=True)
...
This may be irrelevant but it is one thing I tried. Note in routes.py that I have from app import app, db, if I remove app and add from flask import current_app then the #app decorators show as undefined.
Another point, because its a problem with routes. If I change the last line of __init__.py to from app import routes, models I get a different error.
flask.cli.NoAppException
flask.cli.NoAppException: While importing "metapplica", an ImportError was raised:
Traceback (most recent call last):
File "c:\users\markko~1\dropbox\python\projects\metapp~1\venv\lib\site-packages\flask\cli.py", line 236, in locate_app
__import__(module_name)
File "C:\Users\Mark Kortink\Dropbox\Python\projects\metapplica\metapplica.py", line 1, in <module>
from app import create_app, db, cli
File "C:\Users\Mark Kortink\Dropbox\Python\projects\metapplica\app\__init__.py", line 75, in <module>
from app import routes, models
File "C:\Users\Mark Kortink\Dropbox\Python\projects\metapplica\app\routes.py", line 8, in <module>
from app import app, db
ImportError: cannot import name 'app' from 'app' (C:\Users\Mark Kortink\Dropbox\Python\projects\metapplica\app\__init__.py)
It was this error that led me to try the current_app change mentioned above.
I start the app like this.
cd C:\Users\...\myapp
venv\Scripts\activate
set FLASK_APP=app.py
set FLASK_DEBUG=1
flask run
I know the problem is probably really basic but can anyone see why the above code would give a URL not found or not be able to find the routes?
=== NEXT PHASE ================
Following the recommendations from #silver below my new names are: -
myapp
runapp.py
...
/mapp
__init__.py
...
I went through all my code and changed from app[.xxx] import yyy to from myapp[.xxx] import yyy. This flushed out a few new errors where I was referencing app which I fixed by substituting current_app.
My new error is
RuntimeError
RuntimeError: Working outside of application context.
This typically means that you attempted to use functionality that needed
to interface with the current application object in some way. To solve
this, set up an application context with app.app_context(). See the
documentation for more information.
Traceback (most recent call last)
File "C:\Users\Mark Kortink\Dropbox\Python\projects\myapp\runapp.py", line 1, in <module>
from mapp import create_app, db, cli
File "C:\Users\Mark Kortink\Dropbox\Python\projects\myapp\mapp\__init__.py", line 75, in <module>
from mapp import routes, models
File "C:\Users\Mark Kortink\Dropbox\Python\projects\myapp\mapp\routes.py", line 16, in <module>
#current_app.before_request
Without being able to run it myself it's a little hard to be sure.
But I think this is the crux of the matter:
This may be irrelevant but it is one thing I tried. Note in routes.py that I have from app import app, db, if I remove app and add from flask import current_app then the #app decorators show as undefined.
If you want to register anything to the app that's actually running, it has to be through from flask import current_app. That's the thing about Flask application factories -- you only get access to the name of the application that's actually running in two places:
In the factory function itself: create_app, before you return the app object, and
Via from flask import current_app
It looks like Python is able to successfully import the name app in routes.py, since you say the application starts. The only place that from app import app could resolve to is from your app.py file at the top level of your myapp package. That means that each time routes.py is initialized, it's calling the create_app function, and getting a new app object. So understandably, the top-level app object that Flask is serving is not the same one that has routes registered to it.
I recommend renaming your files so that nothing has the name "app" except the object returned by create_app.
Then, in routes.py try:
from datetime import datetime
from flask import render_template, flash, redirect, url_for, request, g, \
jsonify
from flask import current_app as app_ref
...
from app_internals import db # assuming you've renamed the app package
from app_internals.forms import LoginForm, RegistrationForm, EditProfileForm,
PostForm,ResetPassword,RequestForm, ResetPasswordForm
from app_internals.models import User, Post
...
current_app = app_ref._get_current_object()
#current_app.route('/', methods=['GET', 'POST'])
#current_app.route('/index', methods=['GET', 'POST'])
#login_required
def index():
form = PostForm()
if form.validate_on_submit():
...
page = request.args.get('page', 1, type=int)
...
return render_template('index.html', title=_('Home'), form=form,
posts=posts.items, next_url=next_url,
prev_url=prev_url)
#current_app.route ....
In case someone is struggling with similar issues (flask 'mysteriously' not serving routes that should be there, perhaps in conjunction with a create_app factory method):
flask routes is actually showing the routes it detects. the output looks like this (for just one 'hello' endpoint at the root url):
Endpoint Methods Rule
-------- ------- -----------------------
hello GET /
static GET /static/<path:filename>
the SERVER_NAME setting can be responsible (this was the case for me). I had changed it to 0.0.0.0 without realizing it makes a difference for the routing. There is a bug report/discussion on github on that topic.
I just ran into this issue too with Miguel Grinberg's tutorial. It's a pretty fantastic tutorial till some of the later sections which feel rushed.
Anyway.
You need to pass the context.
In the factory function you need to do.
def create_app(config_class=Config):
app = Flask(__name__)
with app.app_context():
from app import routes
Then like the person posted above.
for routes.py change all the #app to #current_app
from flask import current_app
#current_app.route('/')
#current_app.route('/index', methods=['GET', 'POST'])
#login_required
def index():
this works for me.
I have a google verification file that I need to have in my root directory. How do I serve it and set up the route correctly in my app.py file? I thought just having it in the static directory would do the trick.
In my app.py file:
import requests; requests = requests.session()
from flask import (
Flask,
g,
session,
request,
render_template,
abort,
json,
jsonify,
make_response
)
from jinja2 import TemplateNotFound
app = Flask(__name__)
...
#app.route('/ping')
def ping():
return "OK"
"""
Catch-All Route
first looks for templates in /templates/pages
then looks in /templates
finally renders 404.html with 404 status
"""
#app.route('/', defaults={'path': 'index'})
#app.route('/<path:path>')
def show_page(path):
if session.get('tracking_url'):
session['session_url'] = False
templates = [t.format(path=path) for t in 'pages/{path}.html', '{path}.html']
g.path = path
try:
return render_template(templates, **site_variables(path))
except TemplateNotFound:
return render_template('404.html', **site_variables(path)), 404
application = app
if __name__ == '__main__':
app.run('0.0.0.0', debug=True)
I've tried adding this but it didn't work:
#app.route('/myfile.html')
def myfile():
return send_from_directory('/static', 'myfile.html')
For a one-off file that Google looks for in the root, I'd just add a specific route:
from flask import send_from_directory
#app.route('/foobar_baz')
def google_check():
return send_from_directory(app.static_folder, 'foobar_baz')
You are free to add in test in show_page(path) to try and serve path with send_from_directory() before you test for a template, of course; the second filename argument can take relative paths.