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Summarizing multiple columns with dplyr? [duplicate]

...brary(dplyr) library(purrrlyr) library(data.table) library(bench) set.seed(123) n <- 10000 df <- data.frame( a = sample(1:5, n, replace = TRUE), b = sample(1:5, n, replace = TRUE), c = sample(1:5, n, replace = TRUE), d = sample(1:5, n, replace = TRUE), grp = sample(1:3, n, replac...
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Python how to write to a binary file?

...FileBytes) bytearray(b'{\x03\xff\x00d') >>> bytes(newFileBytes) '[123, 3, 255, 0, 100]' share | improve this answer | follow | ...
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Retrieving parameters from a URL

... import urlparse url = 'http://example.com/?q=abc&p=123' par = urlparse.parse_qs(urlparse.urlparse(url).query) print par['q'][0], par['p'][0] share | improve this answer ...
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Does Python have “private” variables in classes?

...names the variable. class A: def __init__(self): self.__var = 123 def printVar(self): print self.__var Now, if you try to access __var outside the class definition, it will fail: >>>x = A() >>>x.__var # this will return error: "A has no attribute __var...
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Disabled href tag

... You can use: <a href="/" onclick="return false;">123n</a> share | improve this answer | follow | ...
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Write a number with two decimal places SQL server

...ters to display, and the number of decimal places to display Select Str(12345.6789, 12, 3) displays: ' 12345.679' ( 3 spaces, 5 digits 12345, a decimal point, and three decimal digits (679). - it rounds if it has to truncate, (unless the integer part is too large for the total size, in whic...
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jQuery deferreds and promises - .then() vs .done()

...tion (x) { // Suppose promise returns "abc" console.log(x); return 123; }).then(function (x){ console.log(x); }).then(function (x){ console.log(x) }) The following results will get logged: abc 123 undefined While promise.done(function (x) { // Suppose promise returns "abc" ...
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Why does Javascript's regex.exec() not always return the same value? [duplicate]

...ignment as the loop condition. var re = /foo_(\d+)/g, str = "text foo_123 more text foo_456 foo_789 end text", match, results = []; while (match = re.exec(str)) results.push(+match[1]); DEMO: http://jsfiddle.net/pPW8Y/ If you don't like the placement of the assignment, the loo...
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Git diff output to file preserve coloring

...swered May 5 '14 at 20:37 sk8asd123sk8asd123 1,3851212 silver badges1313 bronze badges ...
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How to filter by IP address in Wireshark?

...can also limit the filter to only part of the ip address. E.G. To filter 123.*.*.* you can use ip.addr == 123.0.0.0/8. Similar effects can be achieved with /16 and /24. See WireShark man pages (filters) and look for Classless InterDomain Routing (CIDR) notation. ... the number after the slash...