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How to round a number to significant figures in Python
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round_sig = lambda f,p: float(('%.' + str(p) + 'e') % f) allows you to adjust the number of significant digits!
– denizb
Aug 6 '17 at 22:43
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How do I select a random value from an enumeration?
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Use Enum.GetValues to retrieve an array of all values. Then select a random array item.
static Random _R = new Random ();
static T RandomEnumValue<T> ()
{
var v = Enum.GetValues (typeof (T));
return (T) v.GetValue (_R.Next(v.Length));
}
Test:
for (in...
How can i tell if an object has a key value observer attached
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Put a try catch around your removeObserver call
@try{
[someObject removeObserver:someObserver forKeyPath:somePath];
}@catch(id anException){
//do nothing, obviously it wasn't attached because an exception was thrown
}
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How to return a value from __init__ in Python?
...at do use this word.
– cs95
Jul 20 '16 at 6:06
1
@Shiva AFAIK, by new weronika meant __new__(self...
Remote connect to clearDB heroku database
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In heroku website, go to My Apps and select the app on which you have installed ClearDB.
On the top corner click on Addons and then select ClearDB MySQL Database.
Once there, click on your database and choose the 'Endpoint Information' tab. There you see your username/password. The URL to the dat...
What is the difference between dict.items() and dict.iteritems() in Python2?
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It's part of an evolution.
Originally, Python items() built a real list of tuples and returned that. That could potentially take a lot of extra memory.
Then, generators were introduced to the language in general, and that method was reimplemented as an ite...
More elegant way of declaring multiple variables at the same time
...variables with Boolean values is the best way to write your routine (especially if they really have one-letter names :)
Depending on what you're doing, it may make sense to use a dictionary instead. For example, if you want to set up Boolean preset values for a set of one-letter flags, you could d...
How to define hash tables in Bash?
...ecuting your script directly, or execute script with bash script. (Not actually executing a Bash script with Bash does happen, and will be really confusing!)
You declare an associative array by doing:
declare -A animals
You can fill it up with elements using the normal array assignment operator....
Generating random numbers in Objective-C
...te the S-Boxes via
arc4random_addrandom().
There is no need to call arc4random_stir() before using arc4random(), since arc4random() automatically
initializes itself.
EXAMPLES
The following produces a drop-in replacement for the traditional rand() and random() functions using
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How to get my IP address programmatically on iOS/macOS?
I would like to obtain my iPad's IP address programmatically.
How can I query the networking subsystem to find out what my IPv4 (and IPv6) addresses are?
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