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Foreign key from one app into another in Django
...d for external use. They can depend on each other and exist mainly to give me a convenient organisation of my files and namespaces. External apps (eg from DjangoPackages) and apps that I might one day contribute to the public, need to be kept as free as such dependencies as possible (although depend...
Scala equivalent of Java java.lang.Class Object
...e Scala Type System",
val c = new C
val clazz = c.getClass // method from java.lang.Object
val clazz2 = classOf[C] // Scala method: classOf[C] ~ C.class
val methods = clazz.getMethods // method from java.lang.Class<T>
The classOf[T] method returns the runtime re...
How to check if a string contains a substring in Bash
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You can use Marcus's answer (* wildcards) outside a case statement, too, if you use double brackets:
string='My long string'
if [[ $string == *"My long"* ]]; then
echo "It's there!"
fi
Note that spaces in the needle string need to be placed between double quotes, and the * wildcard...
The difference between Classes, Objects, and Instances
...s and values. At the theoretical level, a value is a representation for some quantum of information, and a type is a set of values. When we say value X is an instance of type Y, we are simply saying that X is a member of the set of values that is the type Y.
So that's what the term "instance" rea...
How can I create an array with key value pairs?
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How to flush output of print function?
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On Python 3, print can take an optional flush argument
print("Hello world!", flush=True)
On Python 2 you'll have to do
import sys
sys.stdout.flush()
after calling print. By default, print prints to sys.stdout (see the documentation for more about file objects).
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Specifying colClasses in the read.csv
... options in the read.csv function in R. In my data, the first column "time" is basically a character vector while the rest of the columns are numeric.
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Java: Multiple class declarations in one file
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My suggested name for this technique (including multiple top-level classes in a single source file) would be "mess". Seriously, I don't think it's a good idea - I'd use a nested type in this situation instead. Then it's still easy to predic...
Implementing Comments and Likes in database
...ill be allowed to mark an entity as liked (like in FB), tag it and comment .
7 Answers
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