2015-11-02 kk
best practice code style encoding pep8 linter, flake8 package pip virturalenv setup.py http://lingxiankong.github.io/blog/2013/12/23/python-setup/ 继续阅读 »
2014-03-14 Kun Ren
Oftentimes, we obtain a long or a wide table from a certain data source, and it may be the only format we can get. For example, some financial databases provide daily tick data for all stocks in a financial market. The data table may be arranged in a long format like this: 继续阅读 »
2017-05-18 YongHao Hu
###To be or not to be### 我们也许曾经在写注释与不写之间摇晃不已, 不写是因为代码容易变化而注释往往被忽略掉了,这时注释反而有害; 但又因为就算一个有意义的名字 也难以信达雅的传递程序的意义. Elixir 给出了它的答案. But the problem with comments is that they just don’t get maintained. The code changes, the comment gets stale, and it becomes useless. Fortunately, ExUnit has doctest, a tool that extracts 继续阅读 »
2015-08-09 Klaus Ma
What Is Google C++ Mocking Framework? When you write a prototype or test, often it's not feasible or wise to rely on real objects entirely. A mock object implements the same interface as a real object (so it can be used as one), but lets you specify at run time how it will be used and what it should do (which methods 继续阅读 »
2014-03-15 Kun Ren
In R, function may not be as special as it is in other programming languages; it is regarded as one of the many types and can be passed as an argument to some other function. The way we deal with other objects such list and data.frame definitely applies to function. Here is a simple example in which we define two funct 继续阅读 »
2016-10-19 AnnatarHe
go js be
前言 回学校的这么长时间竟然没有写过超过300行的代码。这日子实在是太颓废了。 SICP 暂时看不下去,那么多题静不下心。 可是最近是真的无聊就说新学一门语言吧,刚好公司在用 Go,而且大家都说 Go 语言不错,我就准备学了一下。 继续阅读 »
2017-08-11 AnnatarHe
众所周知,Nginx 使用 异步, 事件驱动来接收连接。这就意味着对于每个请求不会新建一个专用的进程或者线程(就像传统服务端架构一样),它是在一个工作进程中接收多个连接和请求。为了达成这个目标,Nginx 用在一个非阻塞模式下的 sockets 来实现,并使用例如 epoll 和 kqueue 这样高效的方法。 继续阅读 »
2014-11-14 litaotao
1. 直接上正文   正文就是,关于这点,SO已经有多答案了,下面我引用一下投票最多的答案。 Trunk:would be the main body of development, originating from the start of the project until the present. Branch: will be a copy of code derived from a certain point in the trunk that is used for applying major changes to the code while preserving the integrity of the 继续阅读 »
2014-07-25 Kun Ren
(This article is adapted to the latest version of rvest package.) A large proportion of R's power should be attributed to the enormous amount of extension packages. Many packages are published to CRAN. 继续阅读 »
2014-04-08 Kun Ren
In data-driven statistical computing and data analysis, applying a chain of commands step by step is a common situation. However, it is neither straightforward nor flexible to write a group of deeply nested functions. It is because the function that comes later must be written first. 继续阅读 »