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Filtering a data frame by values in a column [duplicate]
...nce we don't want to restrict which columns we get for those rows (we want all of them), we leave the column part of the index pair blank (so there's nothing after the comma). This is syntactic sugar to avoid having to give a vector of all column indices.
– Will
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Autoresizing masks programmatically vs Interface Builder / xib / nib
...ewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin;
All to often I see these margins OR'ed together on one line like the example above. Just hard to read.
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Conditionally Remove Dataframe Rows with R [duplicate]
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Actually, a simpler way of viewing it is: foo.isolated <- subset(foo, !(sid == "sid104" & game.num == 7))
– WGray
Aug 6 '15 at 21:01
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What’s the purpose of prototype? [duplicate]
...-created each time; it exists in one place in the prototype. So when you call someAnimal.set_name("Ubu"); the this context will be set to someAnimal and (the one and only) set_name function will be called.
There is one advantage to using the first syntax though: functions created in this manner...
How to calculate the intersection of two sets? [duplicate]
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Use the retainAll() method of Set:
Set<String> s1;
Set<String> s2;
s1.retainAll(s2); // s1 now contains only elements in both sets
If you want to preserve the sets, create a new set to hold the intersection:
Set<String&g...
Why doesn't calling a Python string method do anything unless you assign its output?
... line:
X = X.replace("hello", "goodbye")
More broadly, this is true for all Python string methods that change a string's content "in-place", e.g. replace,strip,translate,lower/upper,join,...
You must assign their output to something if you want to use it and not throw it away, e.g.
X = X.strip...
backbone.js & underscore.js CDN recommendation?
...some more cdnjs stats and users: w3techs.com/technologies/details/cd-cdnjs/all/all
– Ryan Kirkman
May 8 '13 at 5:10
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New transaction is not allowed because there are other threads running in the session LINQ To Entity
... ToList method to realise the enumerator into a collection. That will read all items from the enumerator and close the connection to the source, so that you can use the connection for other things.
foreach (var p in pp.ToList())
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How do I write a Python dictionary to a csv file? [duplicate]
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Small addition: You can easily print a subset of a dict by using csv.DictWriter(f, ["testing"], extrasaction='ignore')
– Dawodo
Sep 19 '16 at 16:55
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Double negation (!!) in javascript - what is the purpose? [duplicate]
...ue
null to true
+0 to true
-0 to true
'' to true
NaN to true
false to true
All other expressions to false
Then the other ! negates it again. A concise cast to boolean, exactly equivalent to ToBoolean simply because ! is defined as its negation. It’s unnecessary here, though, because it’s only ...