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ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.al
I just discovered a logical bug in my code which was causing all sorts of problems. I was inadvertently doing a bitwise AND instead of a logical AND .
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Change the Target Framework for all my projects in a Visual Studio Solution
I need to change the target framework for all projects. I have many solutions with hundreds of projects.
10 Answers
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Is there a way to ignore header lines in a UNIX sort?
...ific advantage of being able to selectively sort parts
of a piped input. all the other methods suggested will only sort plain files which can be read multiple times. This works on anything.
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add column to mysql table if it does not exist
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OK this is really crude but someone's got to say it. if you are simply running a SQL script from the command line, you can give mysql the --force switch, which means keep going even if there's an error. then, just go for it. you just want...
What is the purpose of willSet and didSet in Swift?
... for instance to notify other objects that the property just changed. When all you have is get/set, you need another field to hold the value. With willSet and didSet, you can take action when the value is modified without needing another field. For instance, in that example:
class Foo {
var myP...
How can I get the concatenation of two lists in Python without modifying either one? [duplicate]
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Actually you can do this by using the a non hidden function: import operator, operator.add(list1, list2)
– e-satis
Apr 13 '11 at 12:28
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How to choose the id generation strategy when using JPA and Hibernate
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The API Doc are very clear on this.
All generators implement the interface org.hibernate.id.IdentifierGenerator. This is a very simple interface. Some applications can choose to provide their own specialized implementations, however, Hibernate provides a range ...
How to modify Github pull request？
...you need more commits
You push c11,c21,c31 to b
The pull request now shows all 6 six commits
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Can I use Objective-C blocks as properties?
... @CharlieMonroe - Yes you are probably right, but dont you need a dealloc implementation to nil or release the block property without ARC? (its been a while since I used non-ARC)
– Robert
Mar 31 '13 at 21:58
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Will using 'var' affect performance?
...ay have chosen an Interface or parent type if you were to set the type manually.
Update 8 Years Later
I need to update this as my understanding has changed. I now believe it may be possible for var to affect performance in the situation where a method returns an interface, but you would have used a...