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What is :: (double colon) in Python when subscripting sequences?
... @UmarAsghar n means start. so the list start from nth index. Basically, [start:stop:step]
– harryghgim
Sep 1 at 11:42
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Implementing slicing in __getitem__
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The __getitem__() method will receive a slice object when the object is sliced. Simply look at the start, stop, and step members of the slice object in order to get the components for the slice.
>>> class C(object):
......
Convert a list of data frames into one data frame
I have code that at one place ends up with a list of data frames which I really want to convert to a single big data frame.
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Why {} + {} is NaN only on the client side? Why not in Node.js?
...le._commandLineAPI = new CommandLineAPI(this._commandLineAPIImpl, isEvalOnCallFrame ? object : null);
expression = "with ((window && window.console && window.console._commandLineAPI) || {}) {\n" + expression + "\n}";
}
var result = evalFunction.call(object, expression...
How to use a custom comparison function in Python 3?
...e a workaround, but I think I am going to lose some performance by passing all the comparison operators < > = to middle man, since my original custom sort is written in C , it had around 1/2x speed of default sort.
– YOU
Mar 28 '10 at 5:26
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What is the most efficient way to loop through dataframes with pandas? [duplicate]
...Note that iterrows is very slow (it converts every row to a series, potentially messing with your data types). When you need an iterator, better to use itertuples
– joris
Jul 29 '15 at 15:46
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Is there a performance difference between i++ and ++i in C++?
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However, if i is an instance of a C++ class, then i++ and ++i are making calls to one of the operator++ functions. Here's a standard pair of these functions:
Foo& Foo::operator++() // called for ++i
{
this->data += 1;
return *this;
}
Foo Foo::operator++(int ignored_dummy_value) ...
Get the name of the currently executing method
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Even better than my first answer you can use __method__:
class Foo
def test_method
__method__
end
end
This returns a symbol – for example, :test_method. To return the method name as a string, call __method__.to_s instead.
Note: This requires Ruby 1.8.7.
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OS X10.9 环境下部署 QT5.3.1 常见的编译问题 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...件中加入对应的SDK版本:
1
QMAKE_MAC_SDK = macosx10.9
3、:-1: error: [ui_mainwindow.h] Trace/BPT trap: 5
dyld: Library not loaded: /work/build/______________________________PADDING______________________________/lib/QtCore.framework/Versio...
jQuery selector regular expressions
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James Padolsey created a wonderful filter that allows regex to be used for selection.
Say you have the following div:
<div class="asdf">
Padolsey's :regex filter can select it like so:
$("div:regex(class, .*sd.*)")
Also, check the official documentation on se...