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Creating a singleton in Python
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class Foo(object):
pass
some_global_variable = Foo()
Modules are imported only once, everything else is overthinking. Don't use singletons and try not to use globals.
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How to remove leading and trailing whitespace in a MySQL field?
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You're looking for TRIM.
UPDATE FOO set FIELD2 = TRIM(FIELD2);
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In-place edits with sed on OS X
...native way is to use built-in substitution in Vim Ex mode, like:
$ ex +%s/foo/bar/g -scwq file.txt
and for multiple-files:
$ ex +'bufdo!%s/foo/bar/g' -scxa *.*
To edit all files recursively you can use **/*.* if shell supports that (enable by shopt -s globstar).
Another way is to use gawk a...
MySQL/SQL: Group by date only on a Datetime column
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Cast the datetime to a date, then GROUP BY using this syntax:
SELECT SUM(foo), DATE(mydate) FROM a_table GROUP BY DATE(a_table.mydate);
Or you can GROUP BY the alias as @orlandu63 suggested:
SELECT SUM(foo), DATE(mydate) DateOnly FROM a_table GROUP BY DateOnly;
Though I don't think it'll make...
How to get the concrete class name as a string? [duplicate]
... Is there a way to get it with the import path? For example, str(type(foo)) == "<class 'never.gonna.give.youup'>" but type(foo).__name__ == "youup". How do I get never.gonna.give.youup?
– Martin Thoma
Apr 29 '19 at 8:00
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C# generics syntax for multiple type parameter constraints [duplicate]
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void foo<TOne, TTwo>()
where TOne : BaseOne
where TTwo : BaseTwo
More info here:
http://msdn.microsoft.com/en-us/library/d5x73970.aspx
shar...
Python-equivalent of short-form “if” in C++ [duplicate]
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While a = 'foo' if True else 'bar' is the more modern way of doing the ternary if statement (python 2.5+), a 1-to-1 equivalent of your version might be:
a = (b == True and "123" or "456" )
... which in python should be shortened to:
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“Parameter” vs “Argument” [duplicate]
...pression used when calling the method.
Consider the following code:
void Foo(int i, float f)
{
// Do things
}
void Bar()
{
int anInt = 1;
Foo(anInt, 2.0);
}
Here i and f are the parameters, and anInt and 2.0 are the arguments.
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How to check whether a string contains a substring in JavaScript?
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ECMAScript 6 introduced String.prototype.includes:
const string = "foo";
const substring = "oo";
console.log(string.includes(substring));
includes doesn’t have Internet Explorer support, though. In ECMAScript 5 or older environments, use String.prototype.indexOf, which returns...
How to expire a cookie in 30 minutes using jQuery?
...ate.setTime(date.getTime() + (minutes * 60 * 1000));
$.cookie("example", "foo", { expires: date });
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