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How to make a flat list out of list of lists?

...ssentially a wrapper around timeit), and found functools.reduce(operator.iconcat, a, []) to be the fastest solution, both when many small lists and few long lists are concatenated. (operator.iadd is equally fast.) Code to reproduce the plot: import functools import itertools import numpy ...
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Serializing object that contains cyclic object value

... if (stack.includes(obj)) return null; let s = stack.concat([obj]); return Array.isArray(obj) ? obj.map(x => decycle(x, s)) : Object.fromEntries( Object.entries(obj) .map(([k, v]) => [k, decycle(v, s)])); } // ...
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Why is it slower to iterate over a small string than a small list?

...string took longer than doing the same operation on a list of small single character strings. Any explanation? It's almost 1.35 times as much time. ...
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Replace all non Alpha Numeric characters, New Lines, and multiple White Space with one Space

.../[\W_]+/g," "); \W is the negation of shorthand \w for [A-Za-z0-9_] word characters (including the underscore) Example at regex101.com share | improve this answer | follo...
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How can I get a file's size in C++? [duplicate]

... #include <fstream> std::ifstream::pos_type filesize(const char* filename) { std::ifstream in(filename, std::ifstream::ate | std::ifstream::binary); return in.tellg(); } See http://www.cplusplus.com/doc/tutorial/files/ for more information on files in C++. edit: this answ...
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Boost.Asio的简单使用(Timer,Thread,Io_service类) - C/C++ - 清泛网 - 专注C/C++及内核技术

...I标准发送数据。) using boost::asio::ip::tcp; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: client <host>" << std::endl; return 1; } 用asio进行网络连接至少需要一个boost::asi...
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What is the default initialization of an array in Java?

...t is a 0. For float/double that is a 0.0 For booleans that is a false. For char that is the null character '\u0000' (whose decimal equivalent is 0). When you create an array of something, all entries are also zeroed. So your array contains five zeros right after it is created by new. Note (based...
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How do I remove the first characters of a specific column in a table?

In SQL, how can I remove the first 4 characters of values of a specific column in a table? Column name is Student Code and an example value is ABCD123Stu1231 . I want to remove first 4 chars from my table for all records ...
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Why can I add named properties to an array as if it were an object?

...cts, just slightly modified (with a few more functions). Functions like: concat every filer forEach join indexOf lastIndexOf map pop push reverse shift slice some sort splice toSource toString unshift valueOf share ...
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How do I detect unsigned integer multiply overflow?

... addcarry_u8 or subborrow_u64). Their signature is a bit obtuse: unsigned char _addcarry_u32(unsigned char c_in, unsigned int src1, unsigned int src2, unsigned int *sum); unsigned char _subborrow_u32(unsigned char b_in, unsigned int src1, unsigned int src2, unsigned int *diff); c_in/b_in is the c...