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ViewDidAppear is not called when opening app from background
I have a View Controller in which my value is 0 (label) and when I open that View Controller from another ViewController I have set viewDidAppear to set value 20 on label. It works fine but when I close my app and than again I open my app but the value doesn't change because viewDidLoad , vie...
财务计算器拓展：复利计算、平均值、中位数、众数、方差计算 - App Invento...
...culator Extension
精心打造的“财务计算器”扩展，为您的Android应用程序增添先进的财务和统计功能。此扩展让您能够执行广泛的财务计算，从简单利息和复利到净现值和投资回报率。它还使您能够进行基本的统计计算，包括计...
Passing a method as a parameter in Ruby
...ult argument in a block declaration like that. So you need to use a splat and setup the default in the proc code itself.
Or, depending on your scope of all this, it may be easier to pass in a method name instead.
def weightedknn(data, vec1, k = 5, weightf = :gaussian)
...
weight = self.send...
Why does direction of index matter in MongoDB?
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MongoDB concatenates the compound key in some way and uses it as the key in a BTree.
When finding single items - The order of the nodes in the tree is irrelevant.
If you are returning a range of nodes - The elements close to each other will be down the same branches of th...
Generating random strings with T-SQL
If you wanted to generate a pseudorandom alphanumeric string using T-SQL, how would you do it? How would you exclude characters like dollar signs, dashes, and slashes from it?
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Can Json.NET serialize / deserialize to / from a stream?
I have heard that Json.NET is faster than DataContractJsonSerializer, and wanted to give it a try...
5 Answers
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Capture keyboardinterrupt in Python without try-except
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Yes, you can install an interrupt handler using the module signal, and wait forever using a threading.Event:
import signal
import sys
import time
import threading
def signal_handler(signal, frame):
print('You pressed Ctrl+C!')
sys.exit(0)
signal.sig...
Postgresql - change the size of a varchar column to lower length
I have a question about the ALTER TABLE command on a really large table (almost 30 millions rows).
One of its columns is a varchar(255) and I would like to resize it to a varchar(40) .
Basically, I would like to change my column by running the following command:
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Unit Testing: DateTime.Now
...it tests that expects the 'current time' to be different than DateTime.Now and I don't want to change the computer's time, obviously.
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How to do something to each file in a directory with a batch script
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Command line usage:
for /f %f in ('dir /b c:\') do echo %f
Batch file usage:
for /f %%f in ('dir /b c:\') do echo %%f
Update: if the directory contains files with space in the names, you need to change the delimiter the for...