大约有 48,000 项符合查询结果（耗时：0.0574秒） [XML]
Version number comparison in Python
... cmp -like function which compares two version numbers and returns -1 , 0 , or 1 based on their compared valuses.
17 A...
Does JavaScript have a method like “range()” to generate a range within the supplied bounds?
...
Numbers
[...Array(5).keys()];
=> [0, 1, 2, 3, 4]
Character iteration
String.fromCharCode(...[...Array('D'.charCodeAt(0) - 'A'.charCodeAt(0) + 1).keys()].map(i => i + 'A'.charCodeAt(0)));
=> "ABCD"
Iteration
for (const x of Array(5).keys()) {
co...
搭建高可用mongodb集群（四）—— 分片 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...了，安装软件！
1、准备机器，IP分别设置为： 192.168.0.136、192.168.0.137、192.168.0.138。
2、分别在每台机器上建立mongodb分片对应测试文件夹。
#存放mongodb数据文件
mkdir -p /data/mongodbtest
#进入mongodb文件夹
cd /data/mongodbtest
3...
Efficient Algorithm for Bit Reversal (from MSB->LSB to LSB->MSB) in C
...here):
unsigned int
reverse(register unsigned int x)
{
x = (((x & 0xaaaaaaaa) >> 1) | ((x & 0x55555555) << 1));
x = (((x & 0xcccccccc) >> 2) | ((x & 0x33333333) << 2));
x = (((x & 0xf0f0f0f0) >> 4) | ((x & 0x0f0f0f0f) << 4));
...
Python 3.x rounding behavior
I was just re-reading What’s New In Python 3.0 and it states:
11 Answers
11
...
Memoization in Haskell?
...efficiently the following function in Haskell, for large numbers (n > 108)
8 Answers
...
Vagrant reverse port forwarding?
...ROR -o IdentitiesOnly=yes -i ~/.vagrant.d/insecure_private_key vagrant@127.0.0.1
SSH supports forwarding ports in the direction you want with the -R guestport:host:hostport option. So, if you wanted to connect to port 12345 on the guest and have it forwarded to localhost:80, you would use this comm...
Fastest way to replace NAs in a large data.table
... a large data.table , with many missing values scattered throughout its ~200k rows and 200 columns. I would like to re code those NA values to zeros as efficiently as possible.
...
std::vector performance regression when enabling C++11
...ck(Item());)
$ g++ -std=c++11 -O3 -flto regr.cpp && perf stat -r 10 ./a.out
Performance counter stats for './a.out' (10 runs):
35.426793 task-clock # 0.986 CPUs utilized ( +- 1.75% )
4 context-switches # 0.116 K/sec ...
Dynamically select data frame columns using $ and a character value
...itten as
`$`(df , V1)
or indeed
`$`(df , "V1")
But...
`$`(df , paste0("V1") )
...for instance will never work, nor will anything else that must first be evaluated in the second argument. You may only pass a string which is never evaluated.
Instead use [ (or [[ if you want to extract only...