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Numbering rows within groups in a data frame
...r) and library(dplyr) answers to make the ranking val column in descending order?
– Przemyslaw Remin
Jul 24 '18 at 9:31
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Access an arbitrary element in a dictionary in Python
...te that "first" may not be an appropriate term here because dict is not an ordered type in Python < 3.6. Python 3.6+ dicts are ordered.
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Where are environment variables stored in registry?
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Remember to restart your system in order to put your changes into effect.
– 0x6B6F77616C74
Aug 6 '12 at 13:57
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When should I use Lazy?
...ou have an entity Customer which has properties for Name, PhoneNumber, and Orders. Name and PhoneNumber are regular strings but Orders is a navigation property that returns a list of every order the customer ever made.
You often might want to go through all your customer's and get their name and ph...
Initializing a static std::map in C++
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No, the danger is that there is nothing saying in which order the static variables should be initialized (at least across compilation units). But this is not a problem linked to this question. This is a general problem with static variables.
– PierreBdR
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RSpec: describe, context, feature, scenario?
...ike this:
#
# The feature/behaviour I'm currently testing
#
describe "item ordering" do
# 1st state of the feature/behaviour I'm testing
context "without a order param" do
...
end
# 2nd state of the feature/behaviour I'm testing
context "with a given order column" do
..
end
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What happens to a detached thread when main() exits?
... is what the _at_thread_exit family of functions was designed for.
So, in order to avoid undefined behaviour in the absence of any implementation guarantees above what the standard requires, you need to (manually) join a detached thread with an _at_thread_exit function doing the signalling or make ...
Why NSUserDefaults failed to save NSMutableDictionary in iOS?
...e all of your keys in the dictionary NSStrings? I think they have to be in order to save the dictionary to a property list.
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C# Sort and OrderBy comparison
I can sort a list using Sort or OrderBy. Which one is faster? Are both working on same
algorithm?
7 Answers
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C++ : why bool is 8 bits long?
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For this reason, it is quite common to use techniques of "bit packing" in order to increase efficiency in using "boolean" base data types. A technique such as enum (in C) with power of 2 coding is a good example. The same sort of trick is found in most languages.
Updated: Thanks to a excellent dis...