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Django Admin - Disable the 'Add' action for a specific model
...also register MyAdmin like: admin.site.register(MyModel, MyModelAdmin) Add all into the admin.py of the models`s app folder.
– djangonaut
Apr 23 '18 at 9:16
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Python: Tuples/dictionaries as keys, select, sort
...es and so on.
I'd like to organize them in a data structure in Python that allows for easy selection and sorting. My idea was to put them into a dictionary with tuples as keys, e.g.,
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Iterate over object keys in node.js
Since Javascript 1.7 there is an Iterator object, which allows this:
5 Answers
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What's the (hidden) cost of Scala's lazy val?
...nswered Jun 15 '10 at 7:51
oxbow_lakesoxbow_lakes
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Select between two dates with Django
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Use the __range operator:
...filter(current_issue__isnull=True, created_at__range=(start_date, end_date))
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How to write to Console.Out during execution of an MSTest test
...with a file upload feature in our web application. It only happens occasionally and without any special pattern. We have been trying to figure it out for a long time, adding debug information anywhere we can think it might help, crawling the logs etc, but we have not been able to reproduce or figure...
How to 'bulk update' with Django?
...ings like incrementing rows:
from django.db.models import F
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)
See the documentation.
However, note that:
This won't use ModelClass.save method (so if you have some logic inside it won't be triggered).
No django signals will be emitte...
How to make a variadic macro (variable number of arguments)
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The reason for ## before VA_ARGS is that it swallows the preceding comma in case the variable-argument list is empty, eg. FOO("a") expands to printf("a"). This is an extension of gcc (and vc++, maybe), C99 requires at least one argument to be present in place of the elli...
Number of elements in a javascript object
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Although JS implementations might keep track of such a value internally, there's no standard way to get it.
In the past, Mozilla's Javascript variant exposed the non-standard __count__, but it has been removed with version 1.8.5.
For cross-browser scripting you're stuck with explicitly ite...
Android: upgrading DB version and adding new table
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1. About onCreate() and onUpgrade()
onCreate(..) is called whenever the app is freshly installed. onUpgrade is called whenever the app is upgraded and launched and the database version is not the same.
2. Incrementing the db version
You need a constructor like:
MyOpenHelp...