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What are the underlying data structures used for Redis?
...every Redis operation you'll find the time complexity in the documentation and, if you have the set of operations and the time complexity, the only other thing you need is some clue about memory usage (and because we do many optimizations that may vary depending on data, the best way to get these la...
What's the difference between equal?, eql?, ===, and ==?
I am trying to understand the difference between these four methods. I know by default that == calls the method equal? which returns true when both operands refer to exactly the same object.
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bool operator ++ and --
... supports ++ (increment) for bool, but not -- (decrement). It this just a random decision, or there is some reason behind this?
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In Python how should I test if a variable is None, True or False
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Don't fear the Exception! Having your program just log and continue is as easy as:
try:
result = simulate(open("myfile"))
except SimulationException as sim_exc:
print "error parsing stream", sim_exc
else:
if result:
print "result pass"
else:
print...
Which characters are valid in CSS class names/selectors?
...racter is a hyphen, the second character must2 be a letter or underscore, and the name must be at least 2 characters long.
-?[_a-zA-Z]+[_a-zA-Z0-9-]*
In short, the previous rule translates to the following, extracted from the W3C spec.:
In CSS, identifiers (including element names, classes, ...
What is better, adjacency lists or adjacency matrices for graph problems in C++?
...ts or adjacency matrix, for graph problems in C++?
What are the advantages and disadvantages of each?
11 Answers
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How do I select elements of an array given condition?
...e elements in y corresponding to elements in x that are greater than 1 and less than 5.
6 Answers
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How to verify an XPath expression in Chrome Developers tool or Firefox's Firebug?
...here for more details):
Search in Elements panel like below
Execute $x() and $$() in Console panel, as shown in Lawrence's answer
Third party extensions (not really necessary in most of the cases, could be an overkill)
Here is how you search XPath in Elements panel:
Press F12 to open Chrome De...
Can you grab or delete between parentheses in vi/vim?
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Various Motions: %
The % command jumps to the match of the item under the cursor. Position the cursor on the opening (or closing) paren and use y% for yanking or d% for deleting everything from the cursor to the matching paren.
This works because % is a...
Ignoring time zones altogether in Rails and PostgreSQL
I'm dealing with dates and times in Rails and Postgres and running into this issue:
2 Answers
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