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How to map with index in Ruby?
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If you're using ruby 1.8.7 or 1.9, you can use the fact that iterator methods like each_with_index, when called without a block, return an Enumerator object, which you can call Enumerable methods like map on. So you can do:
arr.each_with_inde...
How to call a method defined in an AngularJS directive?
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If you want to use isolated scopes you can pass a control object using bi-directional binding = of a variable from the controller scope. You can also control also several instances of the same directive on a page with the same control object.
angular.module('directiveControlDemo...
How to print a groupby object
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Simply do:
grouped_df = df.groupby('A')
for key, item in grouped_df:
print(grouped_df.get_group(key), "\n\n")
This also works,
grouped_df = df.groupby('A')
gb = grouped_df.groups
for key, values in gb.iteritems():
print(df.ix[values], "\n\n...
Oracle “Partition By” Keyword
Can someone please explain what the partition by keyword does and give a simple example of it in action, as well as why one would want to use it? I have a SQL query written by someone else and I'm trying to figure out what it does.
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When should you use constexpr capability in C++11?
It seems to me that having a "function that always returns 5" is breaking or diluting the meaning of "calling a function". There must be a reason, or a need for this capability or it wouldn't be in C++11. Why is it there?
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Is using a lot of static methods a bad thing?
... keep track of internal states. For example, if I need to transform A into B and don't rely on some internal state C that may vary, I create a static transform. If there is an internal state C that I want to be able to adjust, then I add a constructor to set C and don't use a static transform.
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Java generics - why is “extends T” allowed but not “implements T”?
... Java for using always " extends " rather than " implements " for defining bounds of typeparameters.
8 Answers
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bash: shortest way to get n-th column of output
...dly encounter the following form of columnized output from some command in bash (in my case from executing svn st in my Rails working directory):
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Can I call a constructor from another constructor (do constructor chaining) in C++?
... constructors).
The syntax is slightly different from C#:
class Foo {
public:
Foo(char x, int y) {}
Foo(int y) : Foo('a', y) {}
};
C++03: No
Unfortunately, there's no way to do this in C++03, but there are two ways of simulating this:
You can combine two (or more) constructors via defau...
Find the division remainder of a number
How could I go about finding the division remainder of a number in Python?
12 Answers
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