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Hidden features of Ruby
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I actually wrote an gem at one point to do this, but my code was (a) a mess, and (b) slow. I'm very glad that the functionality has made it into core.
– James A. Rosen
Dec 14 '09 at 13:47
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What's better to use in PHP, $array[] = $value or array_push($array, $value)?
...enchmarks, but I personally feel like $array[] is cleaner to look at, and honestly splitting hairs over milliseconds is pretty irrelevant unless you plan on appending hundreds of thousands of strings to your array.
Edit: Ran this code:
$t = microtime(true);
$array = array();
for($i = 0; $i < 1000...
SQL update fields of one table from fields of another one
...agree with @cluesque, but this answer is an excellent way to use values in one column in a table as a lookup table for replacing values in a column in another table (see SO 21657475), so +1 ...
– Victoria Stuart
May 8 '18 at 18:07
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Where does Scala look for implicits?
...alue that can be passed "automatically", so to speak, or a conversion from one type to another that is made automatically.
Implicit Conversion
Speaking very briefly about the latter type, if one calls a method m on an object o of a class C, and that class does not support method m, then Scala will...
How to convert a data frame column to numeric type?
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Here goes: first two columns are character. I've deliberately called 2nd one fake_char. Spot the similarity of this character variable with one that Dirk created in his reply. It's actually a numerical vector converted to character. 3rd and 4th column are factor, and the last one is "purely" numer...
How to find and return a duplicate value in array
...}
I know this isn't very elegant answer, but I love it. It's beautiful one liner code. And works perfectly fine unless you need to process huge data set.
Looking for faster solution? Here you go!
def find_one_using_hash_map(array)
map = {}
dup = nil
array.each do |v|
map[v] = (map[v...
Ruby Regexp group matching, assign variables on 1 line
...ng like this:
#!/usr/bin/env ruby
string = "RyanOnRails: This is a test"
one, two, three = string.match(/(^.*)(:)(.*)/i).captures
p one #=> "RyanOnRails"
p two #=> ":"
p three #=> " This is a test"
Be aware that if no match is found, String#match will return nil, so something like ...
Chain-calling parent initialisers in python [duplicate]
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The way you are doing it is indeed the recommended one (for Python 2.x).
The issue of whether the class is passed explicitly to super is a matter of style rather than functionality. Passing the class to super fits in with Python's philosophy of "explicit is better than impl...
Should 'using' directives be inside or outside the namespace?
...{
double d = Math.PI;
}
}
}
Now imagine that someone adds another file (File2.cs) to the project that looks like this:
// File2.cs
namespace Outer
{
class Math
{
}
}
The compiler searches Outer before looking at those using directives outside the namespace, s...
How do I pass a string into subprocess.Popen (using the stdin argument)?
...e Popen object with
stdin=PIPE. Similarly, to get anything
other than None in the result tuple,
you need to give stdout=PIPE and/or
stderr=PIPE too.
Replacing os.popen*
pipe = os.popen(cmd, 'w', bufsize)
# ==>
pipe = Popen(cmd, shell=True, bufsize=bufsize, stdin=PIPE).s...