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Can dplyr package be used for conditional mutating?
...and the conditions (except for the default value of NA at the end) are mutually exclusive, as is the case in the question, then we can use an arithmetic expression such that each term is multiplied by the desired result using na_if at the end to replace 0 with NA.
df %>%
mutate(g = 2 * (a == 2 ...
Package objects
...
Normally you would put your package object in a separate file called package.scala in the package that it corresponds to. You can also use the nested package syntax but that is quite unusual.
The main use case for package object...
What's the cleanest way of applying map() to a dictionary in Swift?
I'd like to map a function on all keys in the dictionary. I was hoping something like the following would work, but filter cannot be applied to dictionary directly. What's the cleanest way of achieving this?
...
关于php的socket初探 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...塞的古老模型：属于同步阻塞 IO 模型，代码如下：
socket_server.php
<?php
/**
* SocketServer Class
* By James.Huang <shagoo#gmail.com>
**/
set_time_limit(0);
class SocketServer
{
private static $socket;
function SocketServer($port)
{ ...
Best way to parse command-line parameters? [closed]
What's the best way to parse command-line parameters in Scala?
I personally prefer something lightweight that does not require external jar.
...
Converting a Java Keystore into PEM Format
...- keystore in java format.
foo.p12 - keystore in PKCS#12 format.
foo.pem - all keys and certs from keystore, in PEM format.
(This last file can be split up into keys and certificates if you like.)
Command summary - to create JKS keystore:
keytool -keystore foo.jks -genkeypair -alias foo \
...
CMFCTabCtrl的使用、颜色样式调整 - C/C++ - 清泛网 - 专注C/C++及内核技术
...建一个CMFCTabCtrl，并给其添加4个CEdit:
CRect rectTab;
CEdit m_wnd1;
CEdit m_wnd2;
CEdit m_wnd3;
CEdit m_wnd4;
CMFCTabCtrl m_wndTab;
m_wndTabLoc.GetWindowRect (&rectTab);
ScreenToClient (&rectTab);
m_wndTab.Create (CMFCTabCtrl::STYLE_3D, rectTab, this, 1,
CMFCTabCtrl::...
Python time measure function
...e__, (time2-time1)*1000.0))
return ret
return wrap
Note I'm calling f.func_name to get the function name as a string(in Python 2), or f.__name__ in Python 3.
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Sharing a result queue among several processes
... can I share a queue with asynchronous worker processes started with apply_async ? I don't need dynamic joining or anything else, just a way for the workers to (repeatedly) report their results back to base.
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SQLAlchemy: print the actual query
I'd really like to be able to print out valid SQL for my application, including values, rather than bind parameters, but it's not obvious how to do this in SQLAlchemy (by design, I'm fairly sure).
...