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List changes unexpectedly after assignment. How do I clone or copy it to prevent this?
...
You can slice it:
new_list = old_list[:]
Alex Martelli's opinion (at least back in 2007) about this is, that it is a weird syntax and it does not make sense to use it ever. ;) (In his opinion, the next one is more readable).
You can use the built in list() function:
new_list = list(old_list)
...
Why should text files end with a newline?
...essing the last line of a file if it isn't newline terminated.
There's at least one hard advantage to this guideline when working on a terminal emulator: All Unix tools expect this convention and work with it. For instance, when concatenating files with cat, a file terminated by newline will have a...
Can C++ code be valid in both C++03 and C++11 but do different things?
...l, #1 behaviour is unspecified, so i'd count it as undefined behaviour (at least you cannot expect to get a specific result with c++03, now with c++11 you can), #5 uses a non-standard extension of c++. But I guess you're right. The more you look for it, the more examples you'll find which are define...
mongodb group values by multiple fields
...ems to $push to an array.
db.books.aggregate([
{ "$group": {
"_id": {
"addr": "$addr",
"book": "$book"
},
"bookCount": { "$sum": 1 }
}},
{ "$group": {
"_id": "$_id.addr",
"books": {
"$push": {
"...
Batch script: how to check for admin rights
...
This code returns a false positive (at least on Windows 7) if the user is a Power User. A Power User can also "elevate" and then run net session successfully (ERRORLEVEL = 0) - but they don't actually have admin rights. Using openfiles (see answer by Lucretius bel...
How to do exponential and logarithmic curve fitting in Python? I found only polynomial fitting
... giving each entry a "weight" proportional to y. polyfit supports weighted-least-squares via the w keyword argument.
>>> x = numpy.array([10, 19, 30, 35, 51])
>>> y = numpy.array([1, 7, 20, 50, 79])
>>> numpy.polyfit(x, numpy.log(y), 1)
array([ 0.10502711, -0.40116352])
#...
How to efficiently build a tree from a flat structure?
I have a bunch of objects in a flat structure. These objects have an ID and a ParentID property so they can be arranged in trees. They are in no particular order.
Each ParentID property does not necessarily matches with an ID in the structure. Therefore their could be several trees emerging ...
What's the fastest way to merge/join data.frames in R?
...s benchmark data using the OP's examples to show it performs better, or at least highly competitively.
In Java, when should I create a checked exception, and when should it be a runtime exception? [dupli
... what I think: Using CheckedExceptions, I am forced at compile time to at least acknowledge the exception in the caller. With Runtime exceptions, I am not forced to by the compiler, but can write a unit test that makes me deal with it. Since I still believe that the earlier a bug is caught the ch...
Programming with white text on black background?
...long time usage is the top reason.
Emotional Expectation:
Emotionally, at least for some I guess: things related to creation with a dark theme may feels better, like those software; things books alike, e.g. blog or something, light background may better, since it's more expected.
Black for Colors:
...