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How does zip(*[iter(s)]*n) work in Python?
...from i'th element of each of the input sequences. Since both iterators are identical in our case, zip moves the same iterator twice for each 2-element tuple of output.
In [41]: help(zip)
Help on built-in function zip in module __builtin__:
zip(...)
zip(seq1 [, seq2 [...]]) -> [(seq1[0], seq...
std::vector performance regression when enabling C++11
...me optimization (I also pass the -flto flag to gcc 4.7.2), the results are identical:
(I am compiling your original code, with container.push_back(Item());)
$ g++ -std=c++11 -O3 -flto regr.cpp && perf stat -r 10 ./a.out
Performance counter stats for './a.out' (10 runs):
35.426...
Java 8 Streams: multiple filters vs. complex condition
...le filter invocation using a lambda expression with &&.
But, as said, this kind of overhead will be eliminated by the HotSpot optimizer and is negligible.
In theory, two filters could be easier parallelized than a single filter but that’s only relevant for rather computational intense ta...
C++ unordered_map using a custom class type as the key
...ed to define two things:
A hash function; this must be a class that overrides operator() and calculates the hash value given an object of the key-type. One particularly straight-forward way of doing this is to specialize the std::hash template for your key-type.
A comparison function for equality;...
How to trim leading and trailing white spaces of a string?
...World\n " not work :( ... how remove newline?
– KingRider
Jul 19 '17 at 14:26
8
It still trims th...
How to get function parameter names/values dynamically?
... vikasde wants the parameter values in an array also. This is already provided in a local variable named arguments.
excerpt from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions_and_function_scope/arguments:
The arguments object is not an Array. It is similar to an Ar...
What is the difference between 'typedef' and 'using' in C++11?
...edef]/2 A
typedef-name
can also be introduced by an
alias-declaration.
The identifier following the using keyword becomes a
typedef-name and the optional attribute-specifier-seq following the identifier appertains to that typedef-name. Such a
typedef-name has the same semantics as if it were introdu...
Percentage Height HTML 5/CSS
...centage height in CSS, but it just remains the same size as the content inside it. When I remove the HTML 5 <!DOCTYTPE html> however, it works, the <div> taking up the whole page as desired. I want the page to validate, so what should I do?
...
parseInt vs unary plus, when to use which?
...parseFloat parses and builds the string left to right. If they see an invalid character, it returns what has been parsed (if any) as a number, and NaN if none was parsed as a number.
The unary + on the other hand will return NaN if the entire string is non-convertible to a number.
parseInt('2a',10...
Multiple levels of 'collection.defaultdict' in Python
...r @rschwieb's request for D['key'] += 1, we can expand on previous by overriding addition by defining __add__ method, to make this behave more like a collections.Counter()
First __missing__ will be called to create a new empty value, which will be passed into __add__. We test the value, counting o...