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What is lexical scope?
...
I understand them through examples. :)
First, lexical scope (also called static scope), in C-like syntax:
void fun()
{
int x = 5;
void fun2()
{
printf("%d", x);
}
}
Every inner level can access its outer levels.
There is another way, called dynamic scope used by ...
How to install MySQLdb (Python data access library to MySQL) on Mac OS X?
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Update for those using Python3:
You can simply use conda install mysqlclient to install the libraries required to use MySQLdb as it currently exists. The following SO question was a helpful clue: Python 3 ImportError: No module named 'ConfigParser' . Installing mysqlclient will install...
Interfaces — What's the point?
...ntract. A set of public methods any implementing class has to have. Technically, the interface only governs syntax, i.e. what methods are there, what arguments they get and what they return. Usually they encapsulate semantics as well, although that only by documentation.
You can then have differen...
Get list of all routes defined in the Flask app
... with the @app.route('/...') decorator. Is there a way to get a list of all the routes that have been declared throughout my app? Perhaps there is some method I can call on the app object?
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Apply .gitignore on an existing repository already tracking large number of files
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This answer solved my problem:
First of all, commit all pending changes.
Then run this command:
git rm -r --cached .
This removes everything from the index, then just run:
git add .
Commit it:
git commit -m ".gitignore is now working"
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Redirecting Output from within Batch file
... good and fast way that only opens and positions the file once
@echo off
call :sub >output.txt
exit /b
:sub
command1
command2
...
commandN
Edit 2020-04-17
Every now and then you may want to repeatedly write to two or more files. You might also want different messages on the screen. It is sti...
RegEx for Javascript to allow only alphanumeric
I need to find a reg ex that only allows alphanumeric. So far, everyone I try only works if the string is alphanumeric, meaning contains both a letter and a number. I just want one what would allow either and not require both.
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Get nth character of a string in Swift programming language
...ng a linear loop inside another linear loop means this for loop is accidentally O(n2) — as the length of the string increases, the time this loop takes increases quadratically. Instead of doing that you could use the characters's string collection.
– ignaciohugog
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Difference between dispatch_async and dispatch_sync on serial queue?
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I do mean serial execution. In point of view that all tasks are executed serial regards to other tasks in the same queue. Of cause it still can be concurrent regards to other queues. It is the whole point of GCD that tasks can be dispatched and executed concurrently.
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How to convert An NSInteger to an int?
... front of the NSInteger? For example, (int)myInteger whenever you want to call the integer form, so that you do not have to create a new variable.
– chandhooguy
Dec 28 '14 at 22:05
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