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What is a NullReferenceException, and how do I fix it?
.... This means you either set it to null, or you never set it to anything at all.
Like anything else, null gets passed around. If it is null in method "A", it could be that method "B" passed a null to method "A".
null can have different meanings:
Object variables which are uninitialized and hence poi...
Convert.ChangeType() fails on Nullable Types
...g.
– Anders Lindén
Nov 5 '18 at 10:32
Is there any particular reason to create the safeValue variable as opposed to j...
How to implement a binary tree?
...ice implementation. I'm just here to point out some style stuff. python usually does node is not None instead of your (node!=None). Also, you can use the __str__ function instead of the printTree method.
– Jeff Mandell
Oct 18 '15 at 2:30
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Understanding NSRunLoop
... run loop directly, though there are some (networking) components that may allow you to specify which run loop they will use for I/O processing.
A run loop for a given thread will wait until one or more of its input sources has some data or event, then fire the appropriate input handler(s) to proce...
What does “hashable” mean in Python?
...y and a set member, because these data structures use the hash value internally.
All of Python’s immutable built-in objects are hashable, while no mutable containers (such as lists or dictionaries) are. Objects which are instances of user-defined classes are hashable by default; they all comp...
How to compare times in Python?
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132
You can't compare a specific point in time (such as "right now") against an unfixed, recurring ...
C#: Printing all properties of an object [duplicate]
Is there a method built in to .NET that can write all the properties and such of an object to the console? Could make one using reflection of course, but I'm curious to if this already exists... especially since you can do it in Visual Studio in the Immediate Window. There you can an object name (wh...
How to set up Spark on Windows?
... http://spark.apache.org/docs/latest/building-spark.html
Download and install Maven, and set MAVEN_OPTS to the value specified in the guide.
But if you're just playing around with Spark, and don't actually need it to run on Windows for any other reason that your own machine is running Windows, I'd...
How can I create directories recursively? [duplicate]
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Specifically: os.makedirs(os.path.join("/home/dail", "first", "second", "third"))
– mseery
May 14 '11 at 22:41
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Any way to properly pretty-print ordered dictionaries?
...
– CHINTAN VADGAMA
Sep 23 '19 at 23:32
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