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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...
What's the (hidden) cost of Scala's lazy val?
...nswered Jun 15 '10 at 7:51
oxbow_lakesoxbow_lakes
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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...
Date vs DateTime
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Unfortunately, not in the .Net BCL. Dates are usually represented as a DateTime object with the time set to midnight.
As you can guess, this means that you have all the attendant timezone issues around it, even though for a Date object you'd want absolutely no timezone han...
How to intercept touches events on a MKMapView or UIWebView objects?
...lot of hackish programming that imperfectly duplicates Apple's code, especially in the case of multitouch.
Here's what I do: Implement a gesture recognizer that cannot be prevented and that cannot prevent other gesture recognizers. Add it to the map view, and then use the gestureRecognizer's touc...
Android Use Done button on Keyboard to click button
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You can use this one also (sets a special listener to be called when an action is performed on the EditText), it works both for DONE and RETURN:
max.setOnEditorActionListener(new OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView v, int acti...
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 ...
C# 4.0 optional out/ref arguments
Does C# 4.0 allow optional out or ref arguments?
9 Answers
9
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Python argparse: Make at least one argument required
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args = vars(parser.parse_args())
if not any(args.values()):
parser.error('No arguments provided.')
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Git - Undo pushed commits
...lution that keeps no traces of the "undo".
NOTE: don't do this if someone allready pulled your change
(I would use this only on my personal repo)
do:
git reset <previous label or sha1>
this will re-checkout all the updates locally (so git status will list all updated files)
then you "do ...