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Add column with number of days between dates in DataFrame pandas
I want to subtract dates in 'A' from dates in 'B' and add a new column with the difference.
4 Answers
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Difference between git checkout --track origin/branch and git checkout -b branch origin/branch
Does anybody know the difference between these two commands to switch and track a remote branch?
4 Answers
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What is the fastest way to get the value of π?
I'm looking for the fastest way to obtain the value of π, as a personal challenge. More specifically, I'm using ways that don't involve using #define constants like M_PI , or hard-coding the number in.
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How to do case insensitive string comparison?
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The simplest way to do it (if you're not worried about special Unicode characters) is to call toUpperCase:
var areEqual = string1.toUpperCase() === string2.toUpperCase();
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Pass all variables from one shell script to another?
Lets say I have a shell / bash script named test.sh with:
7 Answers
7
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CASCADE DELETE just once
I have a Postgresql database on which I want to do a few cascading deletes. However, the tables aren't set up with the ON DELETE CASCADE rule. Is there any way I can perform a delete and tell Postgresql to cascade it just this once? Something equivalent to
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Inheriting constructors
...tended). For more see Wikipedia C++11 article. You write:
class A
{
public:
explicit A(int x) {}
};
class B: public A
{
using A::A;
};
This is all or nothing - you cannot inherit only some constructors, if you write this, you inherit all of them. To inherit only selected ones y...
In C/C++ what's the simplest way to reverse the order of bits in a byte?
While there are multiple ways to reverse bit order in a byte, I'm curious as to what is the "simplest" for a developer to implement. And by reversing I mean:
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How do I concatenate or merge arrays in Swift?
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You can concatenate the arrays with +, building a new array
let c = a + b
print(c) // [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]
or append one array to the other with += (or append):
a += b
// Or:
a.append(contentsOf: b) // Swift 3
a.appendContentsOf(b) // Swift 2
a...
Multiple inheritance/prototypes in JavaScript
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Multiple inheritance can be achieved in ECMAScript 6 by using Proxy objects.
Implementation
function getDesc (obj, prop) {
var desc = Object.getOwnPropertyDescriptor(obj, prop);
return desc || (obj=Object.getPrototypeOf(obj) ? getDesc(obj, prop...