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Check variable equality against a list of values
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GumboGumbo
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Does use of final keyword in Java improve the performance?
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edited Nov 25 '10 at 17:35
answered Nov 25 '10 at 17:11
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Pandas dataframe get first row of each group
...column:
>>> df.groupby('id').first().reset_index()
id value
0 1 first
1 2 first
2 3 first
3 4 second
4 5 first
5 6 first
6 7 fourth
To get n first records, you can use head():
>>> df.groupby('id').head(2).reset_index(drop=True)
id value
0 ...
How to get a number of random elements from an array?
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edited Feb 20 '18 at 17:21
answered Oct 9 '13 at 10:52
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How to deep copy a list?
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E0_copy is not a deep copy. You don't make a deep copy using list() (Both list(...) and testList[:] are shallow copies).
You use copy.deepcopy(...) for deep copying a list.
deepcopy(x, memo=None, _nil=[])
Deep copy opera...
Why would finding a type's initializer throw a NullReferenceException?
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with csc test.cs:
(196c.1874): Access violation - code c0000005 (first chance)
mscorlib_ni!System.RuntimeType.GetConstructorImpl(System.Reflection.BindingFlags, System.Reflection.Binder, System.Reflection.CallingConventions, System.Type[], System.Reflection.ParameterModifier[])+0x...
What is the advantage of GCC's __builtin_expect in if else statements?
...e the assembly code that would be generated from:
if (__builtin_expect(x, 0)) {
foo();
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} else {
bar();
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}
I guess it should be something like:
cmp $x, 0
jne _foo
_bar:
call bar
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jmp after_if
_foo:
call foo
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after_if:
You can see that the instr...
Does the ternary operator exist in R?
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306
As if is function in R and returns the latest evaluation, if-else is equivalent to ?:.
> a ...
Procedure expects parameter which was not supplied
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answered Dec 15 '08 at 15:20
HLGEMHLGEM
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