I have a Pyramid app, I split models AND views into separate files in following manner:
How do I split models.py into different files for different models in Pyramid?
One small consequence for views is that since I have them in separate view files in a "views" package is that they cannot find models.py, now models package, since it resides in parent directory.
That is, it used to be:
models.py
views.py
Now it's:
views/__init__.py
views/view1.py
views/view2.py
models/__init__.py
models/model1.py
models/model2.py
Therefore, importing from models in a view results in:
from models import (
ImportError: No module named models
Now, I can work around this by adding following path search module extension in views/__init__.py:
sys.path.append(os.path.dirname(os.path.dirname(__file__)))
But that's kind of kludgy. Is there a better, maybe Pyramid-specific solution?
This is not really pyramid specific, it is just python.
See https://docs.python.org/2/tutorial/modules.html#packages
for a detailed explanation.
You want to
import models.model1
Or
from models.model2 import (...)
I'm late, but it can help some other person.
For solve this, you need to specify your project name. In your case, if the project name is projet_name import your models like this.
from project_name.models.model1 import *
or
import project_name.models.model1
I suppose is not the best way, but it work fine for me.
Related
I know this is a strange question but I am lost on what to do. i cloned pinry... It is working and up . I am trying to find django.views.generic. I have searched the directory in my text editor, I have looked in django.views. But I cannot see generic (only a folder with the name "generic"). I cant understand where the generic file is . It is used in many imports and to extend classes but I cannot find the file to see the import functions. I have a good understanding of files and imports and i would say at this stage I am just above noob level. So is there something I am missing here. How come i cannot find this file? If i go to from django.core.urlresolvers import reverse, I can easly find this but not
eg : from django.views.generic import CreateView
Where is generic?
Try running this from a Python interpreter:
>>> import django.views.generic
>>> django.views.generic.__file__
This will show you the location of the gerneric as a string path. In my case the output is:
'/.../python3.5/site-packages/django/views/generic/__init__.py'
If you look at this __init__.py you will not see the code for any of the generic *View classes. However, these classes can still be imported from the path django.views.generic (if I am not mistaken, this is because the *View classes are part of the __all__ list in django/views/generic/__init__.py). In the case of CreateView, it is actually in django/views/generic/edit.py, although it can be imported from django.views.generic, because of the way the __init__.py is set up.
This is technique is generally useful when you want to find the path to a .py file. Also useful: if you use it on its own in a script (print(__file__)), it will give you the path to the script itself.
How can I import all models in the settings.py in INSTALLED_APPS? When i`m trying to insert some model there is an error occurred: "no models named app1_model"
-ProjectName
--ProjectName
---models
----__init__.py
----admin.py
----app_1_model
----....
----app_n_model
---templates
---__init__.py
---settings.py
---urls.py
---wsgi.py
--manage.py
^ Structure of project ^
The INSTALLED_APPS is for apps not for models. Models are classes that live within your app, usually in /«app_name»/models.py.
I think you have misunderstood how a Django project is structured. Try working through a tutorial example.
a typical structure:
/«project»/«app_name»/models.py
and in settings:
INSTALLED_APPS = [ ... '«app_name»' ... ]
Your path will contain the base project directory, so you can import your app where you need it.
And to use them:
from «app_name».models import *
Although it is always best not to import *, instead, name the classes you wish to import.
To answer the question in the comment:
If you don't like the idea of storing all your models in one file (even though it is normal to do this), you can create a module called models. To do this, create a directory called /«project»/«app_name»/models, inside it put __init__.py (to declare it as a module) and then create your files inside there. You then need to import your file contents into the module in __init__.py. You should read about Python modules to understand this.
To answer the second comment question:
To view models in admin, you should create an admin file with model admin objects.
And finally:
Please read through the tutorials to ensure you have a thorough understanding of Django. Otherwise you're wasting your own time!
This happens in Django context, but the question is not Django specific.
I'm trying to split my big urls.py into smaller and more manageable chunks (app includes, third-party modules, search, admin, development and so on). So instead of urls.py, I'm using urls/ directory now, with urls/__init__.py containing code like this:
import admin
urlpatterns += admin.urlpatterns
Now I've got into trouble with third-party modules. For example, I'm overriding a bunch of URLs and views for django-messages, and so I've put all of it into urls/messages.py. It turns out, I can't import django-messages' views then, since
from messages.views import inbox
inside urls/messages.py tries to import from local directory first, finds a messages module, but can't import messages.views then, since urls/messages/views.py is obviously absent. I wouldn't like having to rename my modules to something like urls.messages_urls, but I haven't found a way to explicitely tell Python to import the "other" messages.views. Neither would I like to specify my imported views via strings, even though I can do that in Django.
How can I solve this situation cleanly?
This is the wrong way to do it.
Django has a method for splitting urls.py into separate files, and that is to use include(). Keep the urls for each application in its own urls.py, and include them into the main one.
For those who could not find it, I was hitting ambiguous import errors. For example, in a django project, let's say I have this tree :
tax module
models module
init.py
tax.py
foo.py
In init.py, I want to import tax.models.tax.Tax.
So I write :
from tax.models.tax import Tax
But python does not find the correct import (it looks for models inside tax.models) and throws
ImportError: No module named models
You have indeed understood that it's all about relative imports. python first looks in the current module. If the first part of your import exists in the current module, it fails.
This behaviour has been fixed in Python 2.5 (and may have become default in Python 3.0), you just have to add :
from __future__ import absolute_import
before your absolute imports.
Have a look at Python 2.5 introduces absolute imports for more thorough information.
Have you tried:
from django.contrib.messages.views import inbox
Untested, but I'd think the full import would work as expected.
This is a pretty simple django patterns question. My manager code usually lives in models.py, but what happens when models.py is really huge? Is there any other alternative pattern to letting your manager code live in models.py for maintainability and to avoid circular imports?
A question may be asked as to why models.py is so huge, but let's just assume it's size and breadth of utility is justified.
I prefer to keep my models in models.py and managers in managers.py (forms in forms.py) all within the same app. For more generic managers, I prefer to keep them in core.managers if they can be re-used for other apps. In some of our larger apps with models/modelname.py that will contains a manager and the model code which doesn't seem bad.
Your best bet with a large set of models is to use django modules to your advantage, and simply create a folder named models. Move your old models.py into this models folder, and rename it __init__.py. This will allow you to then separate each model into more specific files inside of this model folder.
You would then only need to import each model into your __init__.py's namespace.
So, for instance, you might want to separate it into:
yourapp/
models/
__init__.py # This file should import anything from your other files in this directory
basic.py # Just an example name
morespecificmodels.py # Just an example name
managers.py # Might want to separate your manager into this
Then your __init__.py can just be:
from basic import * # You should replace * with each models name, most likely.
from managers import YourManager # Whatever your manager is called.
This is the structure that I use when my model files get huge, however I try to separate things into more pluggable apps as often as possible - so this is rarely used by me.
Hope this helps.
I always place mine in managers.py. If you have a circular import issue remember that a) You can reference the model class for a manager at self.model, and b) You can do imports inside of functions.
What I did when building Django apps was to create a [modelname].py file with just the specific model code, manager code and sometimes form code and used an __init__.py file to import then all in the models directory. This helped me atleast in keeping it managable.
I'd like to move my models to a separate directory, similar to the way it's done with Rails to cut down on code clutter. Is there any way to do this easily?
Thanks,
Collin
I assume you're using the basic webkit and not Django or something fancy. In that case just create a subdirectory called models. Put any python files you use for your models in here. Create also one blank file in this folder called __init__.py.
Then in your main.py or "controller" or what have you, put:
import models
at the top.
You just created a python package.
Brandon's answer is what I do. Furthermore, I rather like Rails's custom of one model per file. I don't stick to it completely but that is my basic pattern, especially since Python tends to encourage more-but-simpler lines of code than Ruby.
So what I do is I make models a package too:
models/
models/__init__.py
models/user.py
models/item.py
models/blog_post.py
In the main .py files I put my basic class definition, plus perhaps some helper functions (Python's module system makes it much safer to keep quickie helper functions coupled to the class definition). And my __init__.py stitches them all together:
"""The application models"""
from user import User
from item import Item
from blog_post import BlogPost
It's slightly redundant but I have lots of control of the namespace.