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Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?
...ensed to do so by the user (e.g. via -ffast-math).
Note that GCC provides __builtin_powi(x,n) as an alternative to pow( ), which should generate an inline multiplication tree. Use that if you want to trade off accuracy for performance, but do not want to enable fast-math.
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Pandas - Get first row value of a given column
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To select the ith row, use iloc:
In [31]: df_test.iloc[0]
Out[31]:
ATime 1.2
X 2.0
Y 15.0
Z 2.0
Btime 1.2
C 12.0
D 25.0
E 12.0
Name: 0, dtype: float64
To select the ith value in the Btime column you could use:
In ...
How to get a string after a specific substring?
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The easiest way is probably just to split on your target word
my_string="hello python world , i'm a beginner "
print my_string.split("world",1)[1]
split takes the word(or character) to split on and optionally a limit to the number of splits.
In this example split on "world" and limit ...
How to deal with cyclic dependencies in Node.js
...orts forward declaration:
module.exports = {
};
// Controllers:
var other_module = require('./other_module');
// Functions:
var foo = function () {
};
// Module exports injects:
module.exports.foo = foo;
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How to store int[] array in application Settings
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public class MyNumberArray : IEnumerable<int>
{
List<int> _values;
public MyNumberArray() { _values = new List<int>(); }
public MyNumberArray(IEnumerable<int> values) { _values = new List<int>(values); }
public static implicit operator List<int>...
How do I activate a virtualenv inside PyCharm's terminal?
... to get the full path to the current directory?
– bad_coder
Jun 22 at 2:38
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What does “abstract over” mean?
...mbers under a single symbol ns:
def sumOf(ns: List[Int]) = ns.foldLeft(0)(_ + _)
And we don't particularly care that it's a List either. List is a specific type constructor (takes a type and returns a type), but we can abstract over the type constructor by specifying which essential characteristi...
How to know/change current directory in Python shell?
...now how to change.
edit
Under Windows:
set PYTHONPATH=%PYTHONPATH%;C:\My_python_lib
(taken from http://docs.python.org/using/windows.html)
edit 2
... and even better: use virtualenv and virtualenv_wrapper, this will allow you to create a development environment where you can add module paths ...
Prevent direct access to a php include file
...tly (mainly a print() vs return()) Here's some modified code:
if(count(get_included_files()) ==1) exit("Direct access not permitted.");
The file being accessed is always an included file, hence the == 1.
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How to get first element in a list of tuples?
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do you mean something like this?
new_list = [ seq[0] for seq in yourlist ]
What you actually have is a list of tuple objects, not a list of sets (as your original question implied). If it is actually a list of sets, then there is no first element because set...