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What are the lesser known but useful data structures?
There are some data structures around that are really useful but are unknown to most programmers. Which ones are they?
83 A...
How to access the ith column of a NumPy multidimensional array?
...nswered Apr 20 '13 at 14:05
AkavallAkavall
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How do I do a not equal in Django queryset filtering?
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Your query appears to have a double negative, you want to exclude all rows where x is not 5, so in other words you want to include all rows where x IS 5. I believe this will do the trick.
results = Model.objects.filter(x=5).exclude(a=true)
To answer your specific question, there is no "...
What are “Groovy” and “Grails” and what kinds of applications are built using them?
... Groovy on Grails?
It doesn't exist under this name anymore. It's simply called Grails now.
What is Groovy?
Originally, a dynamic language for the JVM. However, since Groovy 2.0, both static and dynamic typing are supported.
What is Grails?
Grails (previously known as "Groovy on Grails") is a pro...
What are detached, persistent and transient objects in hibernate?
...(but can still be modified and reattached to a new Session later though).
All this is clearly explained in the whole Chapter 10. Working with objects of the Hibernate documentation that I'm only paraphrasing above. Definitely, a must-read.
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TypeError: method() takes 1 positional argument but 2 were given
...- it's just that the first one is implicit, from the point of view of the caller.
This is because most methods do some work with the object they're called on, so there needs to be some way for that object to be referred to inside the method. By convention, this first argument is called self inside ...
Difference between abstract class and interface in Python
... @L.DeLeo - are you sure your notion of has-a vs. is-a is correct? I generally view the distinction as has-a = member variable vs. is-a = inheritance (parent class or interface). Think Comparable or List in Java; those are is-a relationships, regardless of whether they're interfaces or abstract cl...
Why are Objective-C delegates usually given the property assign instead of retain?
...wner
If B had retained A, A wouldn't be released, as B owns A, thus A's dealloc would never get called, causing both A and B to leak.
You shouldn't worry about A going away because it owns B and thus gets rid of it in dealloc.
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What's the difference between utf8_general_ci and utf8_unicode_ci?
...languages or characters.
On modern servers, this performance boost will be all but negligible. It was devised in a time when servers had a tiny fraction of the CPU performance of today's computers.
Benefits of utf8mb4_unicode_ci over utf8mb4_general_ci
utf8mb4_unicode_ci, which uses the Unicode r...
Access mysql remote database from command line
...ess... login your DB from the local server by typing mysql and then: grant all privileges on *.* to 'root'@'%' identified by 'your-password'
– Nir Alfasi
Apr 8 '13 at 15:45
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