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Django admin: how to sort by one of the custom list_display fields that has no database field
...ustom manager for Customer which includes the number of orders aggregated, and then setting admin_order_field to that aggregate, ie
from django.db import models
class CustomerManager(models.Manager):
def get_query_set(self):
return super(CustomerManager, self).get_query_set().annotat...
How do you determine the ideal buffer size when using FileInputStream?
I have a method that creates a MessageDigest (a hash) from a file, and I need to do this to a lot of files (>= 100,000). How big should I make the buffer used to read from the files to maximize performance?
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How to perform runtime type checking in Dart?
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is and is! can be found in the Operators section of the Dart language tour.
– Curly
Jun 25 '19 at 16:02
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What is the equivalent of “none” in django templates?
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None, False and True all are available within template tags and filters. None, False, the empty string ('', "", """""") and empty lists/tuples all evaluate to False when evaluated by if, so you can easily do
{% if profile.user.first_nam...
ValueError : I/O operation on closed file
Here, p is a dictionary, w and c both are strings.
2 Answers
2
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Abstract Class vs Interface in C++ [duplicate]
... about C++. As you know, there is no clear distinction between interface and abstract class in C++ unlike Java and C#. When would it be more preferrable to use an interface instead of an abstract class in C++? Could you give some examples?
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'Operation is not valid due to the current state of the object' error during postback
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I didn't apply paging on my gridview and it extends to more than 600 records (with checkbox, buttons, etc.) and the value of 2001 didn't work. You may increase the value, say 10000 and test.
<appSettings>
<add key="aspnet:MaxHttpCollectionKeys" value="...
How to prevent line breaks in list items using CSS
...re space by setting li's width to greater values.
[1] § 3. White Space and Wrapping: the white-space property - W3 CSS Text Module Level 3
[2] white-space - CSS: Cascading Style Sheets | MDN
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In c++ what does a tilde “~” before a function name signify?
...scription from ibm.com:
Destructors are usually used to deallocate memory and do other cleanup for a class object and its class members when the object is destroyed. A destructor is called for a class object when that object passes out of scope or is explicitly deleted.
See https://www.ibm.com/sup...
Mark parameters as NOT nullable in C#/.NET?
...pile time to make sure the literal null isn't being used anywhere for it and at run-time throw ArgumentNullException .
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