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How to check if a string is a valid hex color representation?
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/^#[0-9A-F]{6}$/i.test('#AABBCC')
To elaborate:
^ -> match beginning
# -> a hash
[0-9A-F] -> any integer from 0 to 9 and any letter from A to F
{6} -> the previous group appears exactly 6...
How do I upgrade my ruby 1.9.2-p0 to the latest patch level using rvm?
My current version of ruby is ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-darwin10.5.0] but I want to update it to the latest patch level using rvm. How can I do this?
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How to calculate the angle between a line and the horizontal axis?
... the positive Y axis at P1).
angleInDegrees = arctan(deltaY / deltaX) * 180 / PI
But arctan may not be ideal, because dividing the differences this way will erase the distinction needed to distinguish which quadrant the angle is in (see below). Use the following instead if your language includes ...
Is object empty? [duplicate]
...n-zero value
// that that property is correct.
if (obj.length > 0) return false;
if (obj.length === 0) return true;
// If it isn't an object at this point
// it is empty, but it can't be anything *but* empty
// Is it empty? Depends on your application.
if (typeof...
How to drop a list of rows from Pandas dataframe?
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401
Use DataFrame.drop and pass it a Series of index labels:
In [65]: df
Out[65]:
one two...
Generating random whole numbers in JavaScript in a specific range?
...d it. It's a simple rule of three:
Math.random() returns a Number between 0 (inclusive) and 1 (exclusive). So we have an interval like this:
[0 .................................... 1)
Now, we'd like a number between min (inclusive) and max (exclusive):
[0 .................................... 1)...
Sorting 1 million 8-decimal-digit numbers with 1 MB of RAM
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720
+200
There is...
How to validate an email address in PHP
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10 Answers
10
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Which SQL query is faster? Filter on Join criteria or Where clause?
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answered Mar 24 '10 at 17:40
QuassnoiQuassnoi
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Extract first item of each sublist
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201
Using list comprehension:
>>> lst = [['a','b','c'], [1,2,3], ['x','y','z']]
>>&...