In Pyomo, how can I get a list of the variables appearing in a constraint?
I combed through the code in Github, but could not a find any suitable method or attribute for that purpose.
I found the answer myself: model.con1.body._args gets you the desired list.
Related
I don't have a lot of experience in Django and I am a fairly green developer. When I run the localhost I keep getting a Internal Error. I have tried most of the solutions to similar problems here and none of them works. Can anyone help me? The code is not mine so I don't want to alter it as such either.
Here is a picture of the errors I keep getting:
The only thing you can do without altering the code is to enter the value "shop_all_art" in the HomePage table in the database.
Do not share code via images. You should also share the related code.
Your stacktrace clearly says, that Python is not able to access first element of HomePage.objects.filter(value='shop_all_art') in file bidgala/bidgala/pages/views.py. all_art_img is most probably empty.
Looks like all_art_img is empty.
you should check if a Query has any elements before with a method such as
if all_art_img.exists():
all_art_img[0]
I want to add names to my constraints so that it's easier to read the .lp / .gams files.
EDIT: Sorry if I hadn't mentioned, but I want to do this when a constraint list is initialized and constraints are added to it. Pyomo documentation has it only for normal constraints.
I was using PuLP before and was able to just add a string in the end of a constraint. Not sure how to do it with Pyomo. Documentation does not show it anywhere.
This question was answered on the Pyomo forum: https://groups.google.com/forum/?nomobile=true#!topic/pyomo-forum/5DgnivI1JRY
I have a project that is my first serious dive into Mongoid.
I saw a tip to use the following command:
Parent.where('childrens._id' => Moped::BSON::ObjectId(params[:id])).first
But this doesn't work. Error message was:
NameError: uninitialized constant Moped::BSON
I found that BSON is no longer included, so I added it to my Gemfile, as well as Moped. Then, I did another fix I found (placing Moped::BSON=BSON in application.rb).
This still didn't work, but the error changed to:
NoMethodError: undefined method `ObjectId' for BSON:Module
So I am assuming that this method got deprecated or something. Does anyone have any other tips?
Just to be clear, I am finding myself in the situation where I want to sort embedded documents using jquery-sortable. This requires me to update them in the database, but the serialize from that doesn't include the parent document in the hash. So I figured I'd try to get it on the back end using an ID from the embedded document. That is why I need it.
Thanks again for any help you can provide.
Try simply:
Parent.where('childrens._id' => params[:id]).first
I have solved the question though this won't be of much help to people in the future. The requirements have changed and now I am using human-readable strings as IDs to assist in friendly URLs and some other stuff.
Therefore, I don't have any issues with ObjectIds. Cortex's solution should (from what I have read) work for dealing with ObjectIds but I cannot verify it now.
The goal is to make users be more specific when reporting a bug.
Ususally I get a messy report "It doesn't work, please help ASAP!" from a user, so I keep asking the same questions each time -- "The why, the who-what-when, the where, and the how..."
Instead, I want to set a template for a new issue, something like this:
What page did you go? What login did you use?
What did you see?
What did you expect to see?
Why do you think this is a bug?
or whatever.
Is it possible?
This plugin would be very helpful, in your case,
Issue Templates- http://www.redmine.org/plugins/issue_templates
here is a patch for templating issue descriptions. anything beyond that is still underway, and is relevant to the issue mentioned above.
http://www.redmine.org/issues/2931
The link below says that you can for the last year or so:
http://www.redmine.org/issues/1138
But I haven't yet found a description of how this functionality is used. I guess I'll have to slog through some code to find out.
Maybe a possible workaround is to have an issue to use as a template.
Create an issue like this:
name: Bug template
description:
What page did you go?
What login did you use?
What did you see?
What did you expect to see?
Why do you think this is a bug?
Then you can duplicate it each time you need a real issue.
The limit is with issues with subtasks. If you duplicate the parent issue you don't get the subtasks duplicated as well.
I need to find model instances whose FileFields point to a particular set of files. This is probably obvious and documented somewhere but I can't seem to find it: what's the syntax for using FieldField.name in a django filter query? Something like:
models.MyModel.objects.filter(image__name='myfile.jpg')
Nevermind - it's just
models.MyModel.objects.filter(image='myfile.jpg')
a separate issue was causing me to think this wasn't working, but in fact it is.