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Convert a row of a data frame to vector
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edited Oct 30 '19 at 16:15
answered Jan 23 '13 at 16:42
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Can PostgreSQL index array columns?
... CREATE TABLE "Test"("Column1" int[]);
INSERT INTO "Test" VALUES ('{10, 15, 20}');
INSERT INTO "Test" VALUES ('{10, 20, 30}');
CREATE INDEX idx_test on "Test" USING GIN ("Column1");
-- To enforce index usage because we have only 2 records for this test...
SET enable_seqscan ...
One-line list comprehension: if-else variants
...sion you're returning for each element. Thus you need:
[ x if x%2 else x*100 for x in range(1, 10) ]
The confusion arises from the fact you're using a filter in the first example, but not in the second. In the second example you're only mapping each value to another, using a ternary-operator expr...
How to calculate date difference in JavaScript?
...icktoofay
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41
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parseInt vs unary plus, when to use which?
..., here are a few differences I know of:
An empty string "" evaluates to a 0, while parseInt evaluates it to NaN. IMO, a blank string should be a NaN.
+'' === 0; //true
isNaN(parseInt('',10)); //true
The unary + acts more like parseFloat since it also accepts decimals.
parseInt on...
How to add a border just on the top side of a UIView
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202
I consider subclassing UIView and overriding drawRect overkill here. Why not add an extension o...
How do I get logs/details of ansible-playbook module executions?
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answered Sep 15 '13 at 0:23
Lorin HochsteinLorin Hochstein
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The order of keys in dictionaries
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80
You could use OrderedDict (requires Python 2.7) or higher.
Also, note that OrderedDict({'a': 1,...
Convert string to integer type in Go?
... "os"
"strconv"
)
func main() {
flag.Parse()
s := flag.Arg(0)
// string to int
i, err := strconv.Atoi(s)
if err != nil {
// handle error
fmt.Println(err)
os.Exit(2)
}
fmt.Println(s, i)
}
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How does Python 2 compare string and int? Why do lists compare as greater than numbers, and tuples g
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209
From the python 2 manual:
CPython implementation detail: Objects of different types except ...