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cartesian product in pandas
...n unused column name, then add dummy columns with that name, merge, and finally drop the column on the result? Creating, as opposed to reading, data with pandas is just a pain
– Bananach
Oct 10 '19 at 7:31
...
Deleting Objects in JavaScript
...a C++ delete. (And accessing one of them would cause a crash. To make them all turn null would mean having extra work when deleting or extra memory for each object.)
Since Javascript is garbage collected, you don't need to delete objects themselves - they will be removed when there is no way to ref...
Multiline strings in VB.NET
...ring is called implicit line continuation. It has to do with removing the _ from a multi-line statement or expression. This does remove the need to terminate a multiline string with _ but there is still no mult-line string literal in VB.
Example for multiline string
Visual Studio 2008
Dim x = "...
How to get the raw value an field?
...urself.
The W3 also has the same specs and adds:
User agents must not allow the user to set the value to a non-empty
string that is not a valid floating-point number.
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ViewBag, ViewData and TempData
...
1)TempData
Allows you to store data that will survive for a redirect. Internally it uses the Session as backing store, after the redirect is made the data is automatically evicted. The pattern is the following:
public ActionResult Foo(...
Why is Go so slow (compared to Java)?
...n spends runtime supporting language features that the benchmark doesn't really need. In most compiled languages a sufficiently clever compiler could in theory strip out what isn't needed, but there comes a point where you're rigging the demo, since very few real users of the language would write pr...
Leading zeros for Int in Swift
...wn below in order to solve your problem.
#1. Using String's init(format:_:) initializer
Foundation provides Swift String a init(format:_:) initializer. init(format:_:) has the following declaration:
init(format: String, _ arguments: CVarArg...)
Returns a String object initialized by using ...
Golang tests in sub-directory
...
Note that you can run go test "recursively": you need to list all the packages you want to test.
If you are in the root folder of your Go project, type:
go test ./...
The './...' notation is described in the section "Description of package lists" of the "command go":
An import path is...
Binding a Button's visibility to a bool value in ViewModel
...converter:
<ValueConversion(GetType(Boolean), GetType(Visibility))> _
Public Class BoolToVisibilityConverter
Implements IValueConverter
Public Function Convert(ByVal value As Object, ByVal targetType As System.Type, ByVal parameter As Object, ByVal culture As System.Globalization.Cul...
MySQL - length() vs char_length()
...() returns the length of the string measured in characters.
This is especially relevant for Unicode, in which most characters are encoded in two bytes. Or UTF-8, where the number of bytes varies. For example:
select length(_utf8 '€'), char_length(_utf8 '€')
--> 3, 1
As you can see the E...