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Please explain some of Paul Graham's points on Lisp
...is useful to have a clear picture of what happens with Lisp code -- in the form of a stream of characters typed in by the programmer -- on its way to being executed. Let's use a concrete example:
;; a library import for completeness,
;; we won't concern ourselves with it
(require '[clojure.contrib.s...
How to avoid isset() and empty()
... have expanded this topic into a small article, which provides the below information in a somewhat better structured form: The Definitive Guide To PHP's isset And empty
IMHO you should think about not just making the app "E_NOTICE compatible", but restructuring the whole thing. Having hundreds of...
What is a mixin, and why are they useful?
...iple inheritance? Is it just a matter of semantics?
A mixin is a limited form of multiple inheritance. In some languages the mechanism for adding a mixin to a class is slightly different (in terms of syntax) from that of inheritance.
In the context of Python especially, a mixin is a parent class ...
Why are joins bad when considering scalability?
...ed. And the only way you can truly judge "failure" is to set meaningful performance goals and measure against those goals. If you haven't measured, it's too soon to even think about de-normalization.
* That is, exist as entities distinct from mere collections of tables. An additional reason for a r...
Difference between a “coroutine” and a “thread”?
...
Coroutines are a form of sequential processing: only one is executing at any given time (just like subroutines AKA procedures AKA functions -- they just pass the baton among each other more fluidly).
Threads are (at least conceptually) a f...
What Does 'Then' Really Mean in CasperJS
I'm using CasperJS to automate a series of clicks, completed forms, parsing data, etc through a website.
3 Answers
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How to select rows from a DataFrame based on column values?
...rtain techniques. Assume our criterion is column 'A' == 'foo'
(Note on performance: For each base type, we can keep things simple by using the pandas API or we can venture outside the API, usually into numpy, and speed things up.)
Setup
The first thing we'll need is to identify a condition that ...
Why is lock(this) {…} bad?
...
It is bad form to use this in lock statements because it is generally out of your control who else might be locking on that object.
In order to properly plan parallel operations, special care should be taken to consider possible deadl...
The Definitive C++ Book Guide and List
...C++ that covers just about everything in the language in a very accessible format and in great detail. The fifth edition (released August 16, 2012) covers C++11. [Review]
* Not to be confused with C++ Primer Plus (Stephen Prata), with a significantly less favorable review.
Programming: Principles a...
Difference between Node object and Element object?
...list of child nodes and a nextSibling and previousSibling. That structure forms a tree-like hierarchy. The document node would have its list of child nodes (the head node and the body node). The body node would have its list of child nodes (the top level elements in your HTML page) and so on.
So...