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How to overcome TypeError: unhashable type: 'list'
...used to compare dictionary keys during a dictionary lookup quickly.
Internally, hash() method calls __hash__() method of an object which are set by default for any object.
Converting a nested list to a set
>>> a = [1,2,3,4,[5,6,7],8,9]
>>> set(a)
Traceback (most recent call last...
In Eclipse, what can cause Package Explorer “red-x” error-icon when all Java sources compile without
I'm using Eclipse for Java development. All my sources compile fine and the resulting application compiles fine. However, I keep getting an "red-x" error notification in the Package Explorer.
...
Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?
...scientific application. One thing I noticed is that GCC will optimize the call pow(a,2) by compiling it into a*a , but the call pow(a,6) is not optimized and will actually call the library function pow , which greatly slows down the performance. (In contrast, Intel C++ Compiler , executable ...
Transposing a 2D-array in JavaScript
...
array[0].map((_, colIndex) => array.map(row => row[colIndex]));
map calls a provided callback function once for each element in an array, in order, and constructs a new array from the results. callback is invoked only for indexe...
C++ catching all exceptions
...
try{
// ...
} catch (...) {
// ...
}
will catch all C++ exceptions, but it should be considered bad design. You can use c++11's new current_exception mechanism, but if you don't have the ability to use c++11 (legacy code systems requiring a rewrite), then you have no name...
Why can't Python parse this JSON data?
... You have [] when you should have {}:
[] are for JSON arrays, which are called list in Python
{} are for JSON objects, which are called dict in Python
Here's how your JSON file should look:
{
"maps": [
{
"id": "blabla",
"iscategorical": "0"
},
...
Is there a way to make a DIV unselectable?
...t here: msdn.microsoft.com/en-us/library/hh801966(v=vs.85).aspx But I actually tested on IE, and it works correctly.
– KimKha
May 1 '13 at 15:27
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What is a fat JAR? [duplicate]
... Another one is the issue with META-INF files like signature files or SPI (services/package.Class) files which are overwritten by assembly plugin by default. Shade plugin has some special transformers which can merge the files if needed
– MeTTeO
Feb 12 at 9:01
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.rar, .zip files MIME Type
...
actually there's another MIME TYPE for zip, and that's: application/x-zip-compressed
– Kiyarash
Oct 6 '14 at 19:21
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Differences between TCP sockets and web sockets, one more time [duplicate]
...e any barrier (e.g. firewalls) between a Client and a Server offering some services (usually port 80 is accessible from anywhere, by anyone). Client and Server can switch over speaking HTTP in any moment, making use of the same TCP connection (which is never released).
Behind the scenes WebSocket ...