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Add one row to pandas DataFrame
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Consider adding the index to preallocate memory (see my answer)
– FooBar
Jul 23 '14 at 14:22
34
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.toArray(new MyClass[0]) or .toArray(new MyClass[myList.size()])?
... the result may be different.
Benchmark results (score in microseconds, smaller = better):
Benchmark (n) Mode Samples Score Error Units
c.a.p.SO29378922.preSize 1 avgt 30 0.025 ▒ 0.001 us/op
c.a.p.SO29378922.preSize 100 avgt 30 0.15...
When do I use fabs and when is it sufficient to use std::abs?
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In C++, it's always sufficient to use std::abs; it's overloaded for all the numerical types.
In C, abs only works on integers, and you need fabs for floating point values. These are available in C++ (along with all of the C library), but there's no need to use them.
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Where to place $PATH variable assertions in zsh?
...'t listed in any zsh documentation I can find.
This turns out to be partially incorrect: /etc/profile may be sourced by zsh. However, this only occurs if zsh is "invoked as sh or ksh"; in these compatibility modes:
The usual zsh startup/shutdown scripts are not executed. Login shells source /e...
How to create GUID / UUID?
I'm trying to create globally-unique identifiers in JavaScript. I'm not sure what routines are available on all browsers, how "random" and seeded the built-in random number generator is, etc.
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Automatically create an Enum based on values in a database lookup table?
How do I automatically create an enum and subsequently use its values in C# based on values in a database lookup table (using enterprise library data layer)?
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What's the difference between an exclusive lock and a shared lock?
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When the students are reading (shared locks) what is on the board:
They all can read what is on it, together => Multiple shared locks can co-exist.
The teacher waits for them to finish reading before she clears the board to write more => If one or more shared locks already exist, exclusive ...
Value of i for (i == -i && i != 0) to return true in Java
...exception :
The most negative number in two's complement is sometimes called "the
weird number," because it is the only exception.
Of course you have the same phenomenon for Long.Min_Value if you store it in a long variable.
Note that this is only due to choices that were made regarding the...
Legality of COW std::string implementation in C++11
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It's not allowed, because as per the standard 21.4.1 p6, invalidation of iterators/references is only allowed for
— as an argument to any standard library function taking a reference
to non-const basic_string as an argument.
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Calculate text width with JavaScript
...ia css selection rules that you may not be cognizant of at the time. Strip all relevant styles from the container before applying the ones you care about before measuring.
– Jason Bunting
Sep 23 '08 at 0:33
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