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Performance of foreach, array_map with lambda and array_map with static function
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Find MongoDB records where array field is not empty
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873
If you also have documents that don't have the key, you can use:
ME.find({ pictures: { $exists:...
What is the use of the ArraySegment class?
...2, 4 };
array.Dump();
var segment = new ArraySegment<byte>(array, 2, 3);
segment.Dump(); // output: 9, 20, 70
segment.Reverse().Dump(); // output 70, 20, 9
segment.Any(s => s == 99).Dump(); // output false
segment.First().Dump(); // output 9
array.Dump(); // no change
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Best way to create custom config options for my Rails app?
...IG = YAML.load_file("#{RAILS_ROOT}/config/config.yml")[RAILS_ENV]
# Rails 3+
APP_CONFIG = YAML.load_file(Rails.root.join('config/config.yml'))[Rails.env]
If you're using Rails 3, ensure you don't accidentally add a leading slash to your relative config path.
You can then retrieve the value using...
dropping infinite values from dataframes in pandas?
...2]: df.replace([np.inf, -np.inf], np.nan)
Out[12]:
0
0 1
1 2
2 NaN
3 NaN
The same method would work for a Series.
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Correct way to convert size in bytes to KB, MB, GB in JavaScript
...tBytes(1024); // 1 KB
formatBytes('1024'); // 1 KB
formatBytes(1234); // 1.21 KB
formatBytes(1234, 3); // 1.205 KB
Demo / source :
function formatBytes(bytes, decimals = 2) {
if (bytes === 0) return '0 Bytes';
const k = 1024;
const dm = decimals < 0 ? 0 ...
Appending an element to the end of a list in Scala
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List(1,2,3) :+ 4
Results in List[Int] = List(1, 2, 3, 4)
Note that this operation has a complexity of O(n). If you need this operation frequently, or for long lists, consider using another data type (e.g. a ListBuffer).
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What is that “total” in the very first line after ls -l? [closed]
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answered Sep 13 '11 at 12:18
MatMat
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Python creating a dictionary of lists
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>>> d
defaultdict(<type 'list'>, {1: ['1'], 2: ['1', '2'], 3: ['2']})
>>> d.items()
[(1, ['1']), (2, ['1', '2']), (3, ['2'])]
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