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What's the (hidden) cost of Scala's lazy val?
...nswered Jun 15 '10 at 7:51
oxbow_lakesoxbow_lakes
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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...
Non-alphanumeric list order from os.listdir()
...however you want. Based on what you describe,
sorted(os.listdir(whatever_directory))
Alternatively, you can use the .sort method of a list:
lst = os.listdir(whatever_directory)
lst.sort()
I think should do the trick.
Note that the order that os.listdir gets the filenames is probably complet...
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 ...
Python argparse: Make at least one argument required
...
args = vars(parser.parse_args())
if not any(args.values()):
parser.error('No arguments provided.')
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What is this 'Lambda' everyone keeps speaking of?
... 'Lambda' everyone keeps speaking of? A lot of people seem to love it, but all I can gather from it is it is just a way of cramming lots of lines of code into a single expression.
...
Impossible to Install PG gem on my mac with Mavericks
I'm trying to install the pg gem in order to work again with my rails projects. But I get this error:
26 Answers
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Difference between “git checkout ” and “git checkout -- ”
...his is not Git-specific, it's a general Unix command line convention. Normally you use it to clarify that an argument is a file name rather than an option, e.g.
rm -f # does nothing
rm -- -f # deletes a file named "-f"
git checkout1 also takes -- to mean that subsequent arguments are not ...
receiving error: 'Error: SSL Error: SELF_SIGNED_CERT_IN_CHAIN' while using npm
... on ubuntu - I am receiving the error copied below while attempting to install any new modules via npm (I tested socket.io earlier using http, not https though & am wondering if that could have resulted in the issue with npm/unsigned certs). The error pops up once npm tries to resolve the ' https:/...