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Detect if value is number in MySQL
... FROM myTable WHERE concat('',col1 * 1) = col1
It doesn't work for non-standard numbers like
1e4
1.2e5
123. (trailing decimal)
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How do I create a folder in a GitHub repository?
I want to create a folder in a GitHub repository and want to add files in that folder. How do I achieve this?
11 Answers
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What are 'closures' in .NET?
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The general feature of closures is implemented in C# by anonymous methods and lambda expressions.
Here's an example using an anonymous method:
using System;
class Test
{
static void Main()
{
Action action = CreateAction();
action();
action();
}
static Act...
Truncating floats in Python
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First, the function, for those who just want some copy-and-paste code:
def truncate(f, n):
'''Truncates/pads a float f to n decimal places without rounding'''
s = '{}'.format(f)
if 'e' in s or 'E' in s:
return '{0:.{1}f}'.format(f, n)
i, p, d = s.partitio...
What are Flask Blueprints, exactly?
I have read the official Flask documentation on Blueprints and even one or two blog posts on using them.
4 Answers
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How to map atan2() to degrees 0-360
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For those not comfortable with this notation, and without the conversion to degrees built in: if(x>0) {radians = x;} else {radians = 2*PI + x;} so we are just adding 2PI to the result if it is less than 0.
– David Doria
Sep 25 '1...
Android: How to enable/disable option menu item on button click?
...enu() method is called
only once, as described above. The
system keeps and re-uses the Menu you
define in this method until your
activity is destroyed. If you want to
change the Options Menu any time after
it's first created, you must override
the onPrepareOptionsMenu() method.
This ...
How do I execute inserts and updates in an Alembic upgrade script?
...ms.
Note that Alembic provides some basic data functions: op.bulk_insert() and op.execute(). If the operations are fairly minimal, use those. If the migration requires relationships or other complex interactions, I prefer to use the full power of models and sessions as described below.
The followi...
SQLite error 'attempt to write a readonly database' during insert?
... Also, SELinux (if installed) must not be enforcing. Took me a day and a half to figure that one out.
– Steve V.
Dec 19 '10 at 8:31
1
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Checking in packages from NuGet into version control?
...o enable your projects to support pack restore you need to run another command:
Enable-PackageRestore
Now you are ready to commit your code base without the packages folder. The previous command changed your project files so that if packages are missing they get automatically downloaded and added...