I am trying to create a simple Restful service in Python using Flask. I am a little confused with Python modules and how to use them. There have been many questions related tot this, however applying it in my case, doesn't help.
My project directory structure is as below:
algorithmservice
|-api.py
|-resources
|- __init__.py
|- optimization
|- __init__.py
|- instances.py
My instances.py looks like the following
from flask_restful import Resource
class Instance(Resource):
def get(self):
pass
def post(self):
pass
api.py is the following:
from flask import Flask
from flask.ext.restful import Api, Resource
from resources.optimization.instances import *
app = Flask(__name__)
api = Api(app)
When I run the command python api.py, I get the following error:
File "api.py", line 3, in <module>
from resources.optimization.instances import *
ImportError: No module named optimization.instances
i have tried a few other variations of the import statement, but none seem to work.
Related
My goal is to import code into three separate Flask servers. It's not going well. I am on python 3.10.4. I have read perhaps 10 different posts that say things like "put a __init__.py file in your folders" which I have done.
For context I'm not exactly new to Python but I've never learned the importing/module system properly.
I have three Flask servers that run scraping operations on different (but similar) websites. I need them to be separate for various reasons. Anyway, all three need to run the same procedure of getting an IP for a proxy from my proxy provider. For this I have some code:
# we don't need the details here so I snip it to save space
def get_proxy_ip(choice):
r = requests.get(download_list, headers={"Authorization": "Token " + token})
selected_proxy_ip = r.json()["results"][choice]["proxy_address"]
selected_proxy_port = r.json()["results"][choice]["port"]
print(selected_proxy_ip)
return selected_proxy_ip, selected_proxy_port
I want to use this function across all 3 of my Flask servers. Here are some various ways I've tried to import the code into one of the Flask servers:
scrapers/rentCanada/app.py
import requests
from flask import Flask, request, make_response
print("cats")
app = Flask(__name__)
print(__name__, __package__)
# from ..shared.ipgetter import get_proxy_ip
# from ..shared.checker import check_public_ip
# from scrapers.shared.ipgetter import get_proxy_ip
# from scrapers.shared.checker import check_public_ip
import shared.ipgetter as ipgetter
import shared.checker as checker
None of them work.
import shared.ipgetter as ipgetter yields:
cats
__main__ None
Traceback (most recent call last):
File "/home/rlm/Code/canadaAps/scrapers/rentCanada/app.py", line 10, in <module>
import shared.ipgetter as ipgetter
ModuleNotFoundError: No module named 'shared'
ModuleNotFoundError: No module named 'scrapers' yields: ModuleNotFoundError: No module named 'scrapers'
from ..shared.ipgetter import get_proxy_ip yields: ImportError: attempted relative import with no known parent package
At this point you need to see my folder structure.
/scrapers
..__init__.py
..setup.py
../rentCanada
.....__init__.py
.....app.py
../rentFaster
.....__init__.py
.....app.py
../rentSeeker
.....__init__.py
.....app.py
../shared
.....__init__.py
.....ipgetter.py
.....checker.py
I need to be able to use any of the app.py files as entry points.
I also tried setup.py with this:
from setuptools import setup, find_packages
setup(
name = 'tools',
packages = find_packages(),
)
followed by python setup.py install but that didn't make a "tools" import available in app.py like I wanted.
As a final note I suspect someone will tell me to use a blueprint. To me those look like a tool I'd use if I was adding a route. I'm not sure they're right for a simple function, but maybe I'm wrong.
My solution for now is to run Flask with python rentCanada/app.py from the /scrapers folder and use this code
import sys
from pathlib import Path
sys.path.append(str(Path(__file__).parent.parent)) # necessary so util folder is available
import requests
from flask import Flask, request, make_response
print("cats")
app = Flask(__name__)
print(__name__, __package__)
from util.ipgetter import get_proxy_ip
from util.checker import check_public_ip
So the program appends the app.py file folder's parent folder to the path. That makes the util folder (which used to be shared but had a naming conflict) available within the app.py file.
I know this question is a duplicate but I seriously need some help on it. I have searched everywhere for a solution and none of the ones I found helped solved the issue. I would REALLY appreciate some input.
I am working on a project with the following tree structure:
Project
- Source
- Web
- test
- features
testing.features
- steps
testing.py
- app
- __init__.py
- blueprints
communication_bp.py
I am working on a cucumber test code using the behave module and the folder I am working on is the test folder, which include features and steps.
What I am trying to do is to import some methods found in communication_bp.py from the app folder into the cucumber test file "testing.py" in python.
So Line 3 is what I am trying to achieve.
testing.py:
from behave_restful import *
import requests
from blueprints.communication_bp import client_comm
but I keep getting this error.
File "../steps/testing.py", line 3, in <module>
from blueprints.communication_bp import client_comm
ModuleNotFoundError: No module named 'blueprints'
Based on what I have read, the app folder is supposed to have __init__.py, which it does.
I will include what both this file and communication_bp.py file here as well.
init.py
from flask import Flask
from flask_cors import CORS
from flask_jwt_extended import JWTManager
from flask_socketio import SocketIO
# Create the Flask application
rest = Flask(__name__)
...
...
from app.blueprints.communication_bp import communication_bp
...
...
rest.register_blueprint(communication_bp, url_prefix = Config.API_PREFIX)
...
...
communication_bp.py
import sys
import json
from flask import Blueprint, request
...
...
So what exactly does this program wants? What am I missing here?
Starting to do some more advanced processes in flask and I'm having a hard time figuring out how to import my error handling file. Code snipets from init and errors. What's wrong?
I cant get the errors module to load. I've tried doing from errors import *, I get an import error, tried moving it out of the factory still get errors. Tried from errors import *, tried import errors. All fail to some degree. Seems to me I'm missing something simple as a comma or something.
here's some code
first file - init
from flask import Flask, render_template
def create_app():
# Instantiate App
app = Flask(__name__)
with app.app_context():
# Import Blueprints
from .foodtracker.routes import foodtracker
from .fitness.routes import fitness
from .bio.routes import bio
from .home.routes import home
# Import models, and error handler
from . import errors
# Register Blue Prints
app.register_blueprint(foodtracker)
app.register_blueprint(fitness)
app.register_blueprint(bio)
app.register_blueprint(home)
return app
and errors.py
from flask import render_template
from . import app
#app.errorhandler(404)
def pagenotfound(error):
return render_template('/errors/404.html'), 404
directory structure
/fitlife
/fitlife
/bio
/home
/fitness
/foodtracker
__init__.py
errors.py
models.py
You have circular imports. Meaning, the app file tries to import the errors file and the errors file tries to import the app file.
The correct way to handle this would be to 'dumb down' the errors.py file, meaning making it only contain the errors themselves without using the decorator to register them. Then, the errors.py file will not need to import app.
The registration can be done using app.register_error_handler from the higher-level file, instead.
I have a Flask application with this error:
ImportError: No module named annotaria, referer: http://ltw1413.web.cs.unibo.it/
So, my root in web server is:
/home/web/ltw1413/html
Inside html folder I have:
One folder named "annotaria
One file .wsgi named "wsgi.wsgi"
My file .wsgi is:
import sys
sys.path.insert(0, '/home/web/ltw1413/html')
from annotaria import app as application
Inside my folder "annotaria" I have:
"Static" folder : inside stylesheet and js
"Templates" folder : inside html
"run.py" : file python where I have my application
run.py is this:
from pydoc import html
from annotaria import app
from flask import Flask, render_template, redirect, request
import json
import urllib2
import urlparse
import re
import string
import os
from SPARQLWrapper import SPARQLWrapper, JSON
from rdflib import Graph, BNode, Literal, Namespace
from time import strftime
import urllib2
import BeautifulSoup
app = Flask(__name__)
#app.route('/')
def index():
return render_template('index.html')
#app.route('/index.html')
def reloader():
return render_template('index.html')
# other app.route()...
if __name__ == '__main__':
app.run(debug=True)
How can I find a solution? Where is my error?
Lots of errors here...
annotaria is not found on path (that is why it says... well.. exactly that).
In your code you also redefine app: you import it from annotaria and then redefine it in app = Flask(...
Others mentioned individual errors, but it would be helpful to understand the big picture. First of all, let's assume the following structure:
/home/web/ltw1413/html
- wsgi.wsgi
- annotaria/
- __init.py__
- run.py
- static/
- templates
Like Klaus mentioned, you need __init__.py to tell Python that annotaria is a valid package. But then your wsgi.wsgi file needs to import the app from the run module:
from annotaria.run import app as application
You also need to remove this unnecessary import from run.py, since you instantiate a new application:
from annotaria import app
Because there is no application to import, you instantiate a new Flask application.
Finally, make sure that the app runs manually before you start deploying it.
I have built is a simple web app with Flask and Python, which I intend to upload to Heroku.
When starting my app locally, with the following script:
#!venv/bin/python
from app import app
app.run(debug = True)
I get this error message:
Traceback (most recent call last):
File "./run.py", line 2, in <module>
from app import app, mail
File "/home/ricardo/personalSite/app/__init__.py", line 3, in <module>
from app import index
File "/home/ricardo/personalSite/app/index.py", line 6, in <module>
from emails import send_email
File "/home/ricardo/personalSite/app/emails.py", line 2, in <module>
from app import app, mail
ImportError: cannot import name mail
So, it cannot import mail.
Inside the app directory I have this __init__.py, here is were I create the Mail object that is ginving me trouble to import:
from flask import Flask
app = Flask(__name__)
from app import index
from flask.ext.mail import Mail
mail = Mail(app)
And this is the file emails.py where I call the send_mail function:
from flask.ext.mail import Message
from app import app, mail
from flask import render_template
from config import ADMINS
from decorators import async
So, according to the error message, the error is in this file, in the from app import app, mail.
What is the problem? Why can't it import mail?
Update:
This is my directory listing:
persSite\
venv\
<virtual environment files>
app\
static\
templates\
__init__.py
index.py
emails.py
decorators.oy
tmp\
run.py
You have a circular dependency. You have to realize what Python is doing when it imports a file.
Whenever Python imports a file, Python looks to see if the file has already started being imported before. Thus, if module A imports module B which imports module A, then Python will do the following:
Start running module A.
When module A tries to import module B, temporarily stop running module A, and start running module B.
When module B then tries to import module A, then Python will NOT continue running module A to completion; instead, module B will only be able to import from module A the attributes that were already defined there before module B started running.
Here is app/__init__.py, which is the first file to be imported.
from flask import Flask
app = Flask(__name__)
from app import index # <-- See note below.
from flask.ext.mail import Mail
mail = Mail(app)
When this file is imported, it is just Python running the script. Any global attribute created becomes part of the attributes of the module. So, by the time you hit the third line, the attributes 'Flask' and 'app' have been defined. However, when you hit the third line, Python begins trying to import index from app. So, it starts running the app/index.py file.
This, of course, looks like the following:
from flask.ext.mail import Message
from app import app, mail # <-- Error here
from flask import render_template
from config import ADMINS
from decorators import async
Remember, when this Python file is being imported, you have thus far only defined Flask and app in the app module. Therefore, trying to import mail will not work.
So, you need to rearrange your code so that if app.index relies on an attribute in app, that app defines that attribute before attempting to import app.index.
This is probably the problem:
from app import app, mail
In the file 'app/emails.py' the import is from the current module, not a nested app module. Try:
from . import app, mail
If it doesn't work, you should update your question with a more detailed directory listing.