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Understanding dict.copy() - shallow or deep?
... 3, 4, 5]}, {1: [1, 2, 3, 4]})
So:
b = a: Reference assignment, Make a and b points to the same object.
b = a.copy(): Shallow copying, a and b will become two isolated objects, but their contents still share the same reference
b = copy.deepcopy(a): Deep copying, a and b's structure and conte...
Getting the last element of a list
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some_list[-1] is the shortest and most Pythonic.
In fact, you can do much more with this syntax. The some_list[-n] syntax gets the nth-to-last element. So some_list[-1] gets the last element, some_list[-2] gets the second to last, etc, all the way down t...
Unpacking, extended unpacking and nested extended unpacking
...lain with a few examples. Since you're talking about evaluating these "by hand," I'll suggest some simple substitution rules. Basically, you might find it easier to understand an expression if all the iterables are formatted in the same way.
For the purposes of unpacking only, the following substit...
Circle-Rectangle collision detection (intersection)
How can I tell whether a circle and a rectangle intersect in 2D Euclidean space? (i.e. classic 2D geometry)
25 Answers
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What are the differences between the threading and multiprocessing modules?
I am learning how to use the threading and the multiprocessing modules in Python to run certain operations in parallel and speed up my code.
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How to request Administrator access inside a batch file
....bat file. The desired behavior is that when they right-click on the file and say Open, they will get one of those UAC dialogs that makes the screen go dark and forces them to answer whether they want to give the application permission to run as administrator. Instead, they are just seeing "Access...
How are the points in CSS specificity calculated
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Pekka's answer is practically correct, and probably the best way to think about the issue.
However, as many have already pointed out, the W3C CSS recommendation states that "Concatenating the three numbers a-b-c (in a number system with a large base) gives the sp...
Fast Linux File Count for a large number of files
...lot of them. Also there will be no output until all of the names are read and sorted. Use the ls -f option to turn off sorting.
ls -f | wc -l
Note that this will also enable -a, so ., .., and other files starting with . will be counted.
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HTML table with fixed headers?
...isplay a long HTML table such that the column headers stay fixed on-screen and do not scroll with the table body. Think of the "freeze panes" effect in Microsoft Excel.
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UnboundLocalError on local variable when reassigned after first use
The following code works as expected in both Python 2.5 and 3.0:
12 Answers
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