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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 do I avoid capturing self in blocks when implementing an API?
... If you're not using Automatic Reference Counting (ARC), you can do this:
__block MyDataProcessor *dp = self;
self.progressBlock = ^(CGFloat percentComplete) {
[dp.delegate myAPI:dp isProcessingWithProgress:percentComplete];
}
The __block keyword marks variables that can be modified inside th...
Why use apparently meaningless do-while and if-else statements in macros?
...mi-colon. Should the user view code not needing one...
doSomething(1) ;
DO_SOMETHING_ELSE(2) // <== Hey? What's this?
doSomethingElseAgain(3) ;
This means the user expects the compiler to produce an error if the semi-colon is absent.
But the real real good reason is that at some time, the ma...
Setting up FTP on Amazon Cloud Server [closed]
...
Connect to your server via SSH: blog.taggesell.de/index.php?/archives/…
– jaminto
Aug 14 '11 at 13:42
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Best way to replace multiple characters in a string?
...ompile('([&#])')
def d(text):
text = RX.sub(r'\\\1', text)
def mk_esc(esc_chars):
return lambda s: ''.join(['\\' + c if c in esc_chars else c for c in s])
esc = mk_esc('&#')
def e(text):
esc(text)
def f(text):
text = text.replace('&', '\&').replace('#', '\#')
de...
Read file from line 2 or skip header row
...
Or use header_line = next(f).
– Samuel
Jan 6 '15 at 23:41
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Bin size in Matplotlib (Histogram)
...width in this example could be found by: (data.max() - data.min()) / number_of_bins_you_want. The + binwidth could be changed to just 1 to make this a more easily understood example.
– Jarad
Jan 22 '18 at 17:31
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Use cases for the 'setdefault' dict method
...ders -- some are optional, but you want defaults for them:
headers = parse_headers( msg ) # parse the message, get a dict
# now add all the optional headers
for headername, defaultvalue in optional_headers:
headers.setdefault( headername, defaultvalue )
...
Cleaner way to update nested structures
...ss, and an address in a person:
val addressZipCodeLens = Lens(
get = (_: Address).zipCode,
set = (addr: Address, zipCode: Int) => addr.copy(zipCode = zipCode))
val personAddressLens = Lens(
get = (_: Person).address,
set = (p: Person, addr: Address) => p.copy(address = addr)...
cancelling a handler.postdelayed process
... this to post a delayed runnable:
myHandler.postDelayed(myRunnable, SPLASH_DISPLAY_LENGTH);
And this to remove it: myHandler.removeCallbacks(myRunnable);
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