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How can I calculate the difference between two dates?
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Not all days have 86400 seconds. For a trivial example that's fine but it's not a good idea in the real world. DST changes, leap seconds, etc can all mess with it. NSCalendar can tell you how many seconds are in a given day.
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cv2.imshow command doesn't work properly in opencv-python
... only works with waitKey():
import cv2
img = cv2.imread('C:/Python27/03323_HD.jpg')
cv2.imshow('ImageWindow', img)
cv2.waitKey()
(The whole message-loop necessary for updating the window is hidden in there.)
share
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How to print matched regex pattern using awk?
...search for pattern using //, then print out the line, which by default is called a record, denoted by $0. At least read up the documentation.
If you only want to get print out the matched word.
awk '{for(i=1;i<=NF;i++){ if($i=="yyy"){print $i} } }' file
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How to print number with commas as thousands separators?
...For Python ≥3.6
Locale aware
import locale
locale.setlocale(locale.LC_ALL, '') # Use '' for auto, or force e.g. to 'en_US.UTF-8'
'{:n}'.format(value) # For Python ≥2.7
f'{value:n}' # For Python ≥3.6
Reference
Per Format Specification Mini-Language,
The ',' option signals the use ...
How to pass table value parameters to stored procedure from .net code
...to work with it. Assuming your table is a list of integers called "dbo.tvp_Int" (Customize for your own table type)
Create this extension method...
public static void AddWithValue_Tvp_Int(this SqlParameterCollection paramCollection, string parameterName, List<int> data)
{
if(paramCollect...
Setting dynamic scope variables in AngularJs - scope.
...one please add a new answer to the question!
Here is the example:
var the_string = 'life.meaning';
// Get the model
var model = $parse(the_string);
// Assigns a value to it
model.assign($scope, 42);
// Apply it to the scope
// $scope.$apply(); <- According to comments, this is no longer need...
Fastest check if row exists in PostgreSQL
...f a single row from the batch exists in the table because then I know they all were inserted.
8 Answers
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What is the exact meaning of IFS=$'\n'?
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Normally bash doesn't interpret escape sequences in string literals. So if you write \n or "\n" or '\n', that's not a linebreak - it's the letter n (in the first case) or a backslash followed by the letter n (in the other two cas...
How is “=default” different from “{}” for default constructor and destructor?
I originally posted this as a question only about destructors, but now I'm adding consideration of the default constructor. Here's the original question:
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Getting the name of the currently executing method
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Thread.currentThread().getStackTrace() will usually contain the method you’re calling it from but there are pitfalls (see Javadoc):
Some virtual machines may, under some circumstances, omit one or more stack frames from the stack trace. In the extreme case, a virtua...