creating an abstraction layer class to manage resources
Hello all, I am not a pyramid expert and I am doing my best to develop further skills. Maybe my idea was already solved in a more elegant and more convenient way, so please, if you know that, answer me, it will be very appreciated. I am developing a project with SQLAlchemy and Beaker Session, to reduce the number of queries I writed down a custom groupfinder for my pages factories. This class get the resources first from the session if they exist and after from SQLAlchemy DBSession, if they are not founded into the session the same class try to load into the server backed session the data for future use. We are talking about very important user data like the group, email, capabilities enabled and so on. Do you think guys this is the best approach to the problem? If it is I can study develop further the interface to produce something for everybody and propose a new pyramid module with a bit of time. I can try to find a way to declare a dynamic number of session keys to fit the needs of the user. thank you for your time in advance. excuse my poor english f. -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: Distribution not found error
On Sat, Feb 18, 2012 at 6:55 AM, Artur Daschevici a.daschev...@gmail.com wrote: Does anyone else have any other ideas...or any ideas on how to debug this better? Have you tried with the activate_this.py script ? http://pypi.python.org/pypi/virtualenv#using-virtualenv-without-bin-python At this point i would pretty much try anything new...well maybe short of reinstalling everything from python up. Your .wsgi is a python script so you can run: C:\\Python\\Scripts\\Python.exe handler.wsgi If you have no traceback then it should work with mod_wsgi too. Add some print statements for debuging. Like print sys.path or import testsite -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en. -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
What are the files located in the AppName.egg-info used for?
Have just run: $ ./env/bin/pcreate --scaffold=starter AppName $ cd AppName $ ./env/bin/python setup.py develop Which resulted in the directory AppName.egg-info being created: $ tree AppName.egg-info/ Taster.egg-info/ ├── dependency_links.txt ├── entry_points.txt ├── not-zip-safe ├── PKG-INFO ├── requires.txt ├── SOURCES.txt └── top_level.txt 0 directories, 7 files Are these files simply logs of the installation process or are they required for anything? -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: What are the files located in the AppName.egg-info used for?
http://docs.pylonsproject.org/projects/pyramid/en/1.3-branch/narr/project.html#the-project-structure Hope that explains it! On 18 Feb 2012, at 16:16, Tjelvar tjelvar.ols...@gmail.com wrote: Have just run: $ ./env/bin/pcreate --scaffold=starter AppName $ cd AppName $ ./env/bin/python setup.py develop Which resulted in the directory AppName.egg-info being created: $ tree AppName.egg-info/ Taster.egg-info/ ├── dependency_links.txt ├── entry_points.txt ├── not-zip-safe ├── PKG-INFO ├── requires.txt ├── SOURCES.txt └── top_level.txt 0 directories, 7 files Are these files simply logs of the installation process or are they required for anything? -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en. -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: What are the files located in the AppName.egg-info used for?
Actually, you want this for the detail on eggs.. http://peak.telecommunity.com/DevCenter/EggFormats On 18 Feb 2012, at 17:24, Simon Yarde simonya...@me.com wrote: http://docs.pylonsproject.org/projects/pyramid/en/1.3-branch/narr/project.html#the-project-structure Hope that explains it! On 18 Feb 2012, at 16:16, Tjelvar tjelvar.ols...@gmail.com wrote: Have just run: $ ./env/bin/pcreate --scaffold=starter AppName $ cd AppName $ ./env/bin/python setup.py develop Which resulted in the directory AppName.egg-info being created: $ tree AppName.egg-info/ Taster.egg-info/ ├── dependency_links.txt ├── entry_points.txt ├── not-zip-safe ├── PKG-INFO ├── requires.txt ├── SOURCES.txt └── top_level.txt 0 directories, 7 files Are these files simply logs of the installation process or are they required for anything? -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en. -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en. -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: creating an abstraction layer class to manage resources
i tend to structure applications - python, php, whatever - like this: - I use multiple Database Handles. This is always at least a reader and a writer. On the database level, the reader is privileged to only select from databases, while the writer may read and write. If the application needs a clustered database, the writer points to Master while the Reader points to Slaves. In terms of database connectivity, Readers are also non-transactional, while Writers are transaction safe. - Whenever visitors deal with /account administration, I always read off the Master and use per-request database queries. I never use cached data. - Whenever visitors deal with consuming content , everything is sourced from the reader. - On login and preference updates, I cache the core user data. I prefer to put this in Memcached ( though now exploring MongoDB and Riak ), and only use the cookie based Session for account identifiers and user-flow logic. I also time this cached data for 10-20 minutes and then force a refresh. The reason for this - if someone is browsing on 2 devices, or home work, they would have 2 different session ids. -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: creating an abstraction layer class to manage resources
On Sat, Feb 18, 2012 at 18:14, Jonathan Vanasco jonat...@findmeon.comwrote: i tend to structure applications - python, php, whatever - like this: - I use multiple Database Handles. This is always at least a reader and a writer. On the database level, the reader is privileged to only select from databases, while the writer may read and write. If the application needs a clustered database, the writer points to Master while the Reader points to Slaves. In terms of database connectivity, Readers are also non-transactional, while Writers are transaction safe. - Whenever visitors deal with /account administration, I always read off the Master and use per-request database queries. I never use cached data. - Whenever visitors deal with consuming content , everything is sourced from the reader. - On login and preference updates, I cache the core user data. I prefer to put this in Memcached ( though now exploring MongoDB and Riak ), and only use the cookie based Session for account identifiers and user-flow logic. I also time this cached data for 10-20 minutes and then force a refresh. The reason for this - if someone is browsing on 2 devices, or home work, they would have 2 different session ids. -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en. Thank you Jonathan, your approach is very interesting, ready to production use. Do you think it is interesting to have a class layer between SQLALchemy and beaker session? I mean... I would like to interface with a class that manage everything, into the view I call an instance to retrieve the data and I don't repeat the code. f. -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: creating an abstraction layer class to manage resources
i personally wouldn' do that, because my SqlAlchemy classes are really just used for populating a read-only cache -- which is a dict -- and creating/editing records. in your case... and I'm just thinking out loud... 1. you could create an abstract class called CacheBacked, which your Reflected/Declared tables would also intherit from. you could then provide a get_by_id(id) function. Calling that could try to load from a cache, and then failover to loading form SqlAlchemy. there are a lot of problems with that approach though, as SqlAlchemy and your transaction layer may try to persist the objects. the interface would be really awkward too. 2. you could create a wrapper class that proxies a bunch of sqlalchemy objects and saves them to a cache.. class CacheBacked(object): wrapped_sqla_class= None data_structure= None def load(id): self.data_structure= load_from_memory() if not data_structure: wrapped_instance= dbSession.query( self.wrapped_sqla_class ).filter_by(id=id).one() self.data_structure= pull_details_of( wrapped_instance ) class Useraccount(): wrapped_sqla_class= models.Useraccount although, honestly, i don't like either of those ideas and wouldn't do them. hopefully someone here has a good idea ( i just felt it worthwhile to discuss bad ideas! ) -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: Limited traversal
On Fri, Feb 17, 2012 at 01:42:04AM +0400, Andrey Popp wrote: On Thu, Feb 16, 2012 at 12:09:36PM -0800, Mike Orr wrote: Second, how can I generate URLs to resources without loading the objects through this interface? The home page queries the 30 most recent incidents and displays links to them. request.resource_url() requires a resource object, but the home page or browse pages query the database directly and get plain ORM objects rather than location-aware ones. I could make the URLs manually but that sucks. I could somehow get the incident resource and append the ID, or get the root resource and append incident and the ID, but that's not much better. That's interesting question. I'm thinking of the following construct: 1. Make your resource graph lazy, e.g. producing only proxies which only knows its location (pk in database in case of SQLAlchemy) and how to load itself (table and parent resources, which impose some query constraints or JOIN clauses). 2. Reuse your resource graph in pyramid's traversal engine and in your home page view: def homepage(): entries_ids = db.entries_ids_for_homepage() entries = [root[entries][id] for id in entries_ids] So you get ``entries`` list of location-aware Entry objects which are loaded only if you access their fields, but not __name__ or __parent__ which allows you to generate URL for them w/o any overhead. If someone is still interested in this approach, I've implemented[1] sqlalchemy.Query.lazy_get(ident) method which works that way. My use-case is different -- to allow User object to be attached on request without touching database (user id is encoded in authc cookie), but I think it should work for constructing lazy resource graph as well. Implementation based on SQLAlchemy mailing list post[2]. [1]: https://gist.github.com/77eb31670a1842f301c2 [2]: https://groups.google.com/forum/?fromgroups#!topic/sqlalchemy/DvofQn6uVI4 -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: What are the files located in the AppName.egg-info used for?
Dear Simon, Thank you for your response. I've had a look at the pages you highlighted. I've also experimented with running the command: $ .../env/bin/pserver development.ini before and after deleting the AppName.egg-info directory. The latter resulting in a distribution not found error: pkg_resources.DistributionNotFound: AppName So would it be correct to say that: The information in the AppName.egg-info directory is required for the pserve, proutes, pshell and ptweens programs to be able to discover and import the application. Regards, Tjelvar -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: What are the files located in the AppName.egg-info used for?
On Sat, Feb 18, 2012 at 5:23 PM, Tjelvar tjelvar.ols...@gmail.com wrote: Dear Simon, Thank you for your response. I've had a look at the pages you highlighted. I've also experimented with running the command: $ .../env/bin/pserver development.ini before and after deleting the AppName.egg-info directory. The latter resulting in a distribution not found error: pkg_resources.DistributionNotFound: AppName So would it be correct to say that: The information in the AppName.egg-info directory is required for the pserve, proutes, pshell and ptweens programs to be able to discover and import the application. Egg-info is the application's metadata. It tells Python what the package's name and version are, which Python packages/modules it contains, which other distributions it depends on, and what its entry points are. All this is defined in the package's setup.py. When you install the package or run python setup.py egg_info, it creates the egg_info directory. pserve calls paste.deploy.loadwsgi.loadapp(), which reads the app section in the INI file, and looks for the entry point specified in the use= line. It calls Setuptools to find and load this entry point. Entry point data is in the egg_info directories, so that's why they must exist. -- Mike Orr sluggos...@gmail.com -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: What are the files located in the AppName.egg-info used for?
Dear Mike, Thank you for clarifying that. Tjelvar -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
Re: Limited traversal
On Sat, Feb 18, 2012 at 3:53 PM, Andrey Popp 8may...@gmail.com wrote: My use-case is different -- to allow User object to be attached on request without touching database (user id is encoded in authc cookie), but I think it should work for constructing lazy resource graph as well. In Pyramid 1.3 I've updated the cookbook to directly support this idea of a lazy get via attaching lazily evaluated properties to the request object. You may consider it as an alternative to a custom Query class. http://docs.pylonsproject.org/projects/pyramid_cookbook/en/latest/auth/user_object.html#making-a-user-object-available-as-a-request-attribute -- You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com. To unsubscribe from this group, send email to pylons-discuss+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en.
