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MongoDB atomic “findOrCreate”: findOne, insert if nonexistent, but do not update
as the title says, I want to perform a find (one) for a document, by _id, and if doesn't exist, have it created, then whether it was found or was created, have it returned in the callback.
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What is the meaning of the /dist directory in open source projects?
Since I first saw a dist/ directory in many open source projects, usually on GitHub, I've been wondering what it means.
4...
How to parse JSON in Scala using standard Scala classes?
... {
"languages": [{
"name": "English",
"is_active": true,
"completeness": 2.5
}, {
"name": "Latin",
"is_active": false,
"completeness": 0.9
}]
}
""".stripMargin
val result = for {
Some(M(m...
List of Big-O for PHP functions
After using PHP for a while now, I've noticed that not all built-in PHP functions are as fast as expected. Consider these two possible implementations of a function that finds if a number is prime using a cached array of primes.
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Convert unix time to readable date in pandas dataframe
...12.15
3 1349979305 12.19
4 1350065705 12.15
In [25]: df['date'] = pd.to_datetime(df['date'],unit='s')
In [26]: df.head()
Out[26]:
date price
0 2012-10-08 18:15:05 12.08
1 2012-10-09 18:15:05 12.35
2 2012-10-10 18:15:05 12.15
3 2012-10-11 18:15:05 12.19
4 2012-10-12 18:15:...
Performance surprise with “as” and nullable types
...lable types, and I'm adding a section about using the "as" operator, which allows you to write:
10 Answers
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How do you mock out the file system in C# for unit testing?
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Edit: Install the NuGet package System.IO.Abstractions.
This package did not exist when this answer was originally accepted. The original answer is provided for historical context below:
You could do it by creating an interface:
inter...
Amazon Interview Question: Design an OO parking lot [closed]
...s.
ParkingSpace has an Entrance.
Entrance has a location or more specifically, distance from Entrance.
ParkingLotSign is a class.
ParkingLot has a ParkingLotSign.
ParkingLot has a finite number of ParkingSpaces.
HandicappedParkingSpace is a subclass of ParkingSpace.
RegularParkingSpace is a s...
How to find unused images in an Xcode project?
Has anyone a one-line to find unused images in an Xcode project? (Assuming all the files are referenced by name in code or the project files - no code generated file names.)
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How to stop unwanted UIButton animation on title change?
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This works for custom buttons:
[UIView setAnimationsEnabled:NO];
[_button setTitle:@"title" forState:UIControlStateNormal];
[UIView setAnimationsEnabled:YES];
For system buttons you need to add this before re-enabling animations (thank you @Klaas):
[_button layoutIfNeeded];
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