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Reasons for using the set.seed function
...set the seed (or choose a seed to pass into set.seed) based on a character string. For example you could have students use their name as the seed then each student has a unique dataset but the instructor can also create the same datasets for grading.
– Greg Snow
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What is a regular expression which will match a valid domain name without a subdomain?
...specs, your specs are wrong. g.co is a valid domain name but g is only one character.
– sch
Apr 24 '12 at 22:23
3
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What does $_ mean in PowerShell?
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Working version with extra pipeline removed. gci | % { add-member -InputObject $_ -Type NoteProperty -Name Bar -Value $_.name -PassThru } | Select Bar
– Xalorous
Nov 23 '15 at 19:27
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Overloading Macro on Number of Arguments
... expand the _COUNT_ARGS(__VA_ARGS__) part, which otherwise is treated as a string.
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How to declare an array in Python?
... contains references to items. Also, underlying array is created with some extra space.
Consequences of this are:
random access is really cheap (arr[6653] is same to arr[0])
append operation is 'for free' while some extra space
insert operation is expensive
Check this awesome table of operation...
Windows 7, 64 bit, DLL problems
...ication refused to start with the error message that API-MS-WIN-CORE-WINRT-STRING-L1-1-0.DLL is not found by simply updating Visual Studio.
I don't think that my build environment (Windows 7 Pro SP1, Visual Studio Ultimate 2012) was messed up completely, it worked fine for most of my projects. But...
Reading a file line by line in Go
...tion into your own function which calls ReadLine in a for-loop.
bufio.ReadString('\n') isn't fully equivalent to ReadLine because ReadString is unable to handle the case when the last line of a file does not end with the newline character.
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How to handle configuration in Go [closed]
...ing/json"
"os"
"fmt"
)
type Configuration struct {
Users []string
Groups []string
}
file, _ := os.Open("conf.json")
defer file.Close()
decoder := json.NewDecoder(file)
configuration := Configuration{}
err := decoder.Decode(&configuration)
if err != nil {
fmt.Println("err...
What is the difference between . (dot) and $ (dollar sign)?
...fore cannot be used with the . operator.
show can take an Int and return a String.
putStrLn can take a String and return an IO ().
You can chain show to putStrLn like this:
(putStrLn . show) (1 + 1)
If that's too many parentheses for your liking, get rid of them with the $ operator:
putStrLn ....
Concatenate multiple result rows of one column into one, group by another column [duplicate]
...
Simpler with the aggregate function string_agg() (Postgres 9.0 or later):
SELECT movie, string_agg(actor, ', ') AS actor_list
FROM tbl
GROUP BY 1;
The 1 in GROUP BY 1 is a positional reference and a shortcut for GROUP BY movie in this case.
string_agg() ...