I have a project structure like this...
app/
main.py
app/
__init__.py
boot.py
server.py
controllers/
__init__.py
home.py
The imports are...
# main.py
from app import server
# server.py
from . import boot
# boot.py
from . import controllers
# controllers/__init__.py
from . import home
# controllers/home.py
from .. import boot
Now all the imports are working except the last one. The error thrown is...
ImportError: cannot import name boot
What's the problem? (I am using Python 3.2)
You are importing boot which is importing controllers, which is then asked to import home, and home then tries to import boot, but it wasn't done importing yet. Don't do this, you are creating a circular dependency here.
Also see Circular import dependency in Python
Related
I have a project structured like so:
/proj
main.py
config/
__init__.py
setup.py
gui/
__init__.py
app.py
The program is run by calling python main.py.
In main.py I have from gui import App.
In gui/__init__.py I have from .app import App.
Lastly, in app.py I have from ..config import configure; this throws a ValueError that reads attempted relative import beyond top-level package. To resolve this, I can alter the strucure:
/proj
main.py
proj/
config/
__init__.py
setup.py
gui/
__init__.py
app.py
But then I have to change the import statments to include proj (i.e. from proj.gui import App). Is it possible to use relative imports in the former case with the current structure? If not, how can I import what I need from the config subpackage?
As strange as it sounds, you can do :
from config import configure
in app.py, for your former case (current structure), because when you run python main.py, it interprets config as the next level package, and .. won't work.
(Btw, I think there is lots of room for Python imports to improve. The current PEP 328 is confusing at best).
I want to use relative import in Python 3.
My project:
main_folder
- __init__.py
- run.py
- tools.py
I want to have in run.py (MyClass declared in __init__.py):
from . import MyClass
And in run.py:
from .tools import my_func
An ImportError is raise.
Alternatively, with absolute import, debugging in PyCharm does not work and the library takes from installed packages, not my directory.
I know one way, but it is terrible:
sys.path.append(os.path.dirname(os.path.realpath(__file__)))
How to use this import in my project?
When you use PyCharm, it automatically makes the current module main, so relative statements like from . import <module> will not work. read more here.
to fix your problem, put the __init__.py and tools.py files in a sub-directory
main_directory/
run.py
sub_directory/
__init__.py
tools.py
in your run.py file, write the following as your import statements
from sub_directory import tools
from sub_directory.__init__ import MyClass
Edit: as #9000 mentioned, you can write from sub_directory import MyClass and achieve the same thing.
Having some issues with importing modules in python. This is my folder structure
my_app/
app.py
__init__.py (I want to import a function from this file)
folder1/
__init.py
method1.py
folder2/
__init__.py
method.py
In my root __init__.py I have this function
def want_to_be_run_elsewhere():
pass
In my app.py, I want to import this function and run it when I start my application, but I'm unsure how to do it.
from my_app import want_to_be_run_elsewhere
This throws a no module named my_app
From what I can tell, I have all the necessary __init__.py files, so maybe it could be sys.path related?
I've read some similar threads on here but I haven't been able to solve this.
Usually you would do the import like
from . import want_to_be_run_elsewhere
This doesn't work here, because you are calling app.py. If you import my_app.app, it is part of the module. If you call it it is not. Importing from the module it is in using . will then not work.
You could either move app.py outside of my_app, removing it from the module and making imports work again.
Or you can use
from __init__ import want_to_be_run_elsewhere
in app.py
I believe
from my_app import want_to_be_run_elsewhere
will only work if you have actually pip install -e my_app/. Then it should work too.
I'm trying to import a python class from another folder of my python package but I this error "No module named models".
It's a Flask project.
-app
|-run.py
|-myapp
|- libs
|- updateto
|- __init__.py (empty)
|- connection.py
|- removeto
|- __init__.py (empty)
|- static
|- templates
|- __init__.py (NOT empty)
|- routes.py
|- models.py
My init.py:
from flask import Flask
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///maindb.db'
from models import db
db.init_app(app)
import myapp.routes
In my models.py I've a class named: application
And in connection.py I want import my class "application".
I've try with "from models import application" but I've this error "no modules named models".
I think it's possible to reach this goal with the modification of the init.py in the "updateto" folder but I'm no sure because I don't clearly understand the functioning of the init.py file...
Thanks
EDIT:
Which is weird, it's if under connection.py I add "import myapp" and "print(help(myapp))", I've this output:
Help on package myapp:
NAME
myapp
FILE
c:\app\myapp\__init__.py
PACKAGE CONTENTS
libs (package)
models
routes
DATA
app = <Flask 'myapp'>
But if I try "from myapp import models" I've this error "ImportError: cannot import name models"
EDIT2:
If I try to add in connection.py "from myapp import app", it works but not if I try to import models... I'm very surprised. I've try to add in myapp/init.py:
__all__ = ["models", "routes]
But same error...
EDIT3:
hummmm I've move all my modules under the libs folder into myapp and when I try to put in connection.py "from model import application" I've always the same error "ImportError: cannot import name application"
Other test in connection.py:
import models
print(models)
Output:
<module 'myapp.models' from 'C:\app\myapp\models.pyc'>
I can import my module named models but I can't import the class under models.py
EDIT4:
Ok, I think I found the problem. It's my ini.py in myapp, because if I comment this file content, the connection.py can now import my class application in models. I run the file run.py which uses routes.py and it's him that calls operation.py
With some tests, I've find the lines who create my error:
from models import db
db.init_app(app)
import myapp.routes
But why????
I don't know about Flask specifically, but in Python you should generally include a __init__.py in every folder and subfolder for them to be recognised as modules and/or packages.
In the diagram you provide, there is no __init__.py in the app folder. Try putting one and re-post if that resolves your problem.
If it doesn't work, try:
import os
print(os.getcwd())
If the current working directory isn't the app directory, you'll have to work around this. One way would be:
import sys
sys.path.append('/path/to/app')
import myapp.models
You can always see what directories are in your search path for modules by checking sys.path.
Update: Sorry I just realized that maybe you' re trying to run connections.py as a script. That would change you working directory to that of connections.py. Try importing connections.py from your main script with import models inside connections.py and see if you get an error.
Update (in reply to Edit 4): (I don't have enough reputation points to comment yet, so I reply here)
from models import db
db.init_app(app)
import myapp.routes
The problem in this piece of code is the import myapp.routes. Change that to import routes and it should work. As a rule of thumb, your main script's directory is your root directory. You can import any module located in your root directory from inside any other module (even modules inside a sub-folder!) with a simple import module.
I have a parent package that has 2 child packages. It looks like this
backend
__init__.py
conf.py
db.py
connections.py
/api
__init__.py
register.py
api.py
/scheduled
__init__.py
helpers.py
All the __init__.py files are empty.
The code in backend/connections.py and backend/conf.py is being used by modules in both packages api and scheduled.
in register.py i have code like
from backend.conf import *
from backend.connections import *
Now when i do python register.py
i get this error
ImportError: No module named backend.conf
Also when i changed from backend.conf import * to from ..conf import * or from .. import conf i get this error
ValueError: Attempted relative import in non-package
What i understand by the above error is that python is not treating the above folders as packages. But i have __init__.py in all the folders. What is wrong?
When you run python register.py, your backend/register.py file is used as the __main__ module of the program, rather than as a module within the backend package. Further more, the Python import path will not automatically include the directory containing the backend directory, which is probably the cause of your problems.
One option that might work is to run your program as python -m backend.register from the top level directory of your project (or set PYTHONPATH so this module can be found). This will search for the script on the normal import path, and then run it as the main program.