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When to use ' (or quote) in Lisp?
...uments passed to it are evaluated. This means you can write this:
(* (+ a 2)
3)
Which in turn evaluates (+ a 2), by evaluating a and 2. The value of the symbol a is looked up in the current variable binding set, and then replaced. Say a is currently bound to the value 3:
(let ((a 3))
(* (+...
How to install mongoDB on windows?
...ng to test out mongoDB and see if it is anything for me. I downloaded the 32bit windows version, but have no idea on how to continue from now on.
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Return first N key:value pairs from dict
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edited Aug 21 '19 at 12:43
ofir_aghai
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combinations between two lists?
...e looking for - see the other answers.
Suppose len(list1) >= len(list2). Then what you appear to want is to take all permutations of length len(list2) from list1 and match them with items from list2. In python:
import itertools
list1=['a','b','c']
list2=[1,2]
[list(zip(x,list2)) for x in ite...
Bash set +x without it being printed
...o find a solution that doesn't use a subshell:
set -x
command
{ set +x; } 2>/dev/null
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Hash Map in Python
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253
Python dictionary is a built-in type that supports key-value pairs.
streetno = {"1": "Sachin ...
How does the extend() function work in jQuery?
...nd works, so I ran a little test:
var a = {foo: 1, bar: 1};
var b = {foo: 2, baz: 2};
var c = {foo: 3};
var r = jQuery.extend(a,b,c);
console.log("A: Foo=" + a.foo + " Bar=" + a.bar + " Baz=" + a.baz);
console.log("B: Foo=" + b.foo + " Bar=" + b.bar + " Baz=" + b.baz);
console.log("C: Foo=" + c.foo...
Why does Math.round(0.49999999999999994) return 1?
....1 This is a specification bug, for precisely this one pathological case.2 Java 7 no longer mandates this broken implementation.3
The problem
0.5+0.49999999999999994 is exactly 1 in double precision:
static void print(double d) {
System.out.printf("%016x\n", Double.doubleToLongBits(d));
}
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Why does ~True result in -2?
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240
int(True) is 1.
1 is:
00000001
and ~1 is:
11111110
Which is -2 in Two's complement1
1 ...