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Simulate first call fails, second call succeeds
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– haggisandchips
Sep 13 '16 at 15:04
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bash assign default value
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edited Dec 14 '10 at 9:29
answered Dec 14 '10 at 9:23
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How to test if list element exists?
... to check that the name is actually defined in the list:
foo <- list(a=42, b=NULL)
foo
is.null(foo[["a"]]) # FALSE
is.null(foo[["b"]]) # TRUE, but the element "exists"...
is.null(foo[["c"]]) # TRUE
"a" %in% names(foo) # TRUE
"b" %in% names(foo) # TRUE
"c" %in% names(foo) # FALSE
...and foo[[...
Cartesian product of x and y array points into single array of 2D points
...mpy.transpose([numpy.tile(x, len(y)), numpy.repeat(y, len(x))])
array([[1, 4],
[2, 4],
[3, 4],
[1, 5],
[2, 5],
[3, 5]])
See Using numpy to build an array of all combinations of two arrays for a general solution for computing the Cartesian product of N arrays.
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React ignores 'for' attribute of the label element
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edited Jun 4 '16 at 2:08
answered Mar 31 '14 at 1:48
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How do I make class methods / properties in Swift?
...y
class var comp: Int { // computed type property
return 42
}
class func alert() { // type method
print("There are \(all.count) foos")
}
}
Foo.alert() // There are 0 foos
let f = Foo()
Foo.all.append(f)
Foo.alert() // There are 1 foos
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Where is a complete example of logging.config.dictConfig?
... Acumenus
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answered Sep 21 '11 at 23:15
DaveDave
9,26744 gold badges292...
Qt c++ aggregate 'std::stringstream ss' has incomplete type and cannot be defined
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answered Aug 1 '12 at 1:46
Luchian GrigoreLuchian Grigore
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ValueError : I/O operation on closed file
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Boris
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answered Sep 23 '13 at 6:09
falsetrufalsetru
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Webrick as production server vs. Thin or Unicorn?
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42
A couple important reasons
it's written in Ruby (see http://github.com/ruby/ruby/tree/trunk/l...