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How to make lists contain only distinct element in Python? [duplicate]
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The simplest is to convert to a set then back to a list:
my_list = list(set(my_list))
One disadvantage with this is that it won't preserve the order. You may also want to consider if a set would be a better data structure to use in the first place, instead of a list.
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Sorting list based on values from another list?
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Shortest Code
[x for _,x in sorted(zip(Y,X))]
Example:
X = ["a", "b", "c", "d", "e", "f", "g", "h", "i"]
Y = [ 0, 1, 1, 0, 1, 2, 2, 0, 1]
Z = [x for _,x in sorted(zip(Y,X))]
print(Z) # ["a", "d", "h", "b", "c", "e", "i", "f"...
Get item in the list in Scala?
...y(Array(1, 2, 3), Array(4, 5, 6))
// 1. paratheses
scala> a.map(_(0))
Array[String] = Array(1, 4)
// 2. apply
scala> a.map(_.apply(0))
Array[String] = Array(1, 4)
// 3. function literal
scala> a.map(a => a(0))
Array[String] = Array(1, 4)
// 4. lift
scala> a.m...
Most efficient way to create a zero filled JavaScript array?
...rray(5) you're creating an object that kinda looks like this: { length: 5, __proto__: Array.prototype } - try console.dir( Array(5) ). Notice that it doesn't have any properties 0, 1, 2, etc. But when you apply that unto the Array constructor, it's like saying Array(undefined, undefined, undefined, ...
What generates the “text file busy” message in Unix?
...tanding the underlying API to better see what is going on.
sleep.c
#define _XOPEN_SOURCE 700
#include <unistd.h>
int main(void) {
sleep(10000);
}
busy.c
#define _XOPEN_SOURCE 700
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <sys/types.h>
#inc...
Listening for variable changes in JavaScript
...ers): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects#Defining_getters_and_setters
You can define an object like this, in which aInternal represents the field a:
x = {
aInternal: 10,
aListener: function(val) {},
set a(val) {
this.aInternal = val;
th...
Is there a command to refresh environment variables from the command prompt in Windows?
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:SetFromReg
"%WinDir%\System32\Reg" QUERY "%~1" /v "%~2" > "%TEMP%\_envset.tmp" 2>NUL
for /f "usebackq skip=2 tokens=2,*" %%A IN ("%TEMP%\_envset.tmp") do (
echo/set %~3=%%B
)
goto :EOF
:: Get a list of environment variables from registry
:GetRegEnv
"%WinDir%\Syst...
What should main() return in C and C++?
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stdlib.h provides EXIT_SUCCESS and EXIT_FAILURE for this purpose
– Clay
Oct 15 '08 at 13:13
21
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Remove ActiveRecord in Rails 3
...r config/application.rb doesn't have require 'rails/all' or require "active_record/railtie". Instead, for a standard Rails setup without ActiveRecord, it should have only the following requires:
require File.expand_path('../boot', __FILE__)
require "action_controller/railtie"
require "action_maile...
'id' is a bad variable name in Python
...() is a fundamental built-in:
Help on built-in function id in module
__builtin__:
id(...)
id(object) -> integer
Return the identity of an object. This is guaranteed to be unique among
simultaneously existing objects. (Hint: it's the object's memory
address.)
In g...