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List of lists changes reflected across sublists unexpectedly
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When you write [x]*3 you get, essentially, the list [x, x, x]. That is, a list with 3 references to the same x. When you then modify this single x it is visible via all three references to it:
x = [1] * 4
l = [x] * 3
print(f"id(x): {id(x)}")
# id(x): 1405608979...
Generate a heatmap in MatPlotLib using a scatter data set
...50 heatmap. If you want, say, 512x384, you can put bins=(512, 384) in the call to histogram2d.
Example:
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Get notified when UITableView has finished asking for data?
...eload its data. So, when the second NSLog is fired, the table view has actually finish asking for data.
I've subclassed UITableView to send methods to the delegate before and after reloadData. It works like a charm.
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How can I use numpy.correlate to do autocorrelation?
...olution, C(t)=∑ -∞ < i < ∞ aivt+i where -∞ < t < ∞, allows for results from -∞ to ∞, but you obviously can't store an infinitely long array. So it has to be clipped, and that is where the mode comes in. There are 3 different modes: full, same, & valid:
"full" mode r...
Get real path from URI, Android KitKat new storage access framework [duplicate]
Before the new gallery access in Android 4.4 (KitKat) I got my real path on the SD card with this method:
9 Answers
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Get full path of the files in PowerShell
I need to get all the files including the files present in the subfolders that belong to a particular type.
14 Answers
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Why does !{}[true] evaluate to true in JavaScript?
...undefined) must therefore be defined. If something is defined then it's usually interpreted as true.
– OozeMeister
Oct 31 '13 at 16:50
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Python memory leaks [closed]
... have a long-running script which, if let to run long enough, will consume all the memory on my system.
9 Answers
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How do I use valgrind to find memory leaks?
...o come to this question and are still new to Linux—you might have to install Valgrind on your system.
sudo apt install valgrind # Ubuntu, Debian, etc.
sudo yum install valgrind # RHEL, CentOS, Fedora, etc.
Valgrind is readily usable for C/C++ code, but can even be used for other
languages wh...
What really is a deque in STL?
I was looking at STL containers and trying to figure what they really are (i.e. the data structure used), and the deque stopped me: I thought at first that it was a double linked list, which would allow insertion and deletion from both ends in constant time, but I am troubled by the promise made ...