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How to extract the n-th elements from a list of tuples?
...
@Wayne Werner: Yep. This stuff was all just passive knowledge (I don't often use it) - but it's good to be reminded now and then so you know where / what to look for...
– Daren Thomas
Jul 22 '10 at 13:14
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Scala: write string to file in one statement
...or encoding-safe. If an exception happens in write(), close will never be called, and the file won't be closed. PrintWriter also uses the default system encoding, which is very bad for portability. And finally, this approach generates a separate class specifically for this line (however, given that ...
From an array of objects, extract value of a property as array
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Check out Lodash's _.pluck() function or Underscore's _.pluck() function. Both do exactly what you want in a single function call!
var result = _.pluck(objArray, 'foo');
Update: _.pluck() has been removed as of Lodash v4.0.0, in favour of _...
Split Python Flask app into multiple files
...like this:
Main.py
from flask import Flask
from AccountAPI import account_api
app = Flask(__name__)
app.register_blueprint(account_api)
@app.route("/")
def hello():
return "Hello World!"
if __name__ == "__main__":
app.run()
AccountAPI.py
from flask import Blueprint
account_api = Bl...
Can Python print a function definition?
...pile a regular expression pattern, returning a pattern object."
return _compile(pattern, flags)
This will work in the interactive prompt, but apparently only on objects that are imported (not objects defined within the interactive prompt). And of course it will only work if Python can find th...
Variable number of arguments in C++?
...u can probably do what you want to do in a safer and simpler way. Technically to use variable number of arguments in C you include stdarg.h. From that you'll get the va_list type as well as three functions that operate on it called va_start(), va_arg() and va_end().
#include<stdarg.h>
int...
What's the (hidden) cost of Scala's lazy val?
...nswered Jun 15 '10 at 7:51
oxbow_lakesoxbow_lakes
127k5252 gold badges305305 silver badges442442 bronze badges
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Scala how can I count the number of occurrences in a list
...", "banana", "apple", "oranges", "oranges")
s.groupBy(identity).mapValues(_.size)
giving a Map with a count for each item in the original sequence:
Map(banana -> 1, oranges -> 3, apple -> 3)
The question asks how to find the count of a specific item. With this approach, the solution w...
How to handle both a single item and an array for the same property using JSON.net
....Categories));
Console.WriteLine();
}
}
}
And finally, here is the output of the above:
email: john.doe@sendgrid.com
timestamp: 1337966815
event: open
categories: newuser, transactional
email: jane.doe@sendgrid.com
timestamp: 1337966815
event: open
categories: olduser
F...
Explicitly select items from a list or tuple
... myBigList[i] for i in [87, 342, 217, 998, 500] ]
20.6 usec: map(myBigList.__getitem__, (87, 342, 217, 998, 500))
22.7 usec: itemgetter(87, 342, 217, 998, 500)(myBigList)
24.6 usec: list( myBigList[i] for i in [87, 342, 217, 998, 500] )
Note that in Python 3, the 1st was changed to be the same as ...