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How can I convert a DateTime to the number of seconds since 1970?
...ateTime variable to Unix time, ie, the number of seconds since Jan 1st, 1970. It looks like a DateTime is actually implemented as the number of 'ticks' since Jan 1st, 0001.
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How do write IF ELSE statement in a MySQL query
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150
You probably want to use a CASE expression.
They look like this:
SELECT col1, col2, (case when...
What is the GAC in .NET?
...s\assembly
C:\Windows\assembly>dir
Directory of C:\Windows\assembly
07/20/2009 02:18 PM <DIR> GAC
06/17/2009 04:22 PM <DIR> GAC_32
06/17/2009 04:22 PM <DIR> GAC_64
06/17/2009 04:22 PM <DIR> GAC_MSIL
...snip...
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Peak memory usage of a linux/unix process
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20 Answers
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Initialise a list to a specific length in Python [duplicate]
How do I initialise a list with 10 times a default value in Python?
3 Answers
3
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css3 实现静态图片闪烁效果 - 更多技术 - 清泛网 - 专注C/C++及内核技术
... ease-in-out;
position: absolute;
}
@-webkit-keyframes start {
0%,30% {opacity: 0;-webkit-transform: translate(0,0);}
60% {opacity: 1;-webkit-transform: translate(0,0);}
100% {opacity: 1;-webkit-transform: translate(0,0);}
}
@-moz-keyframes start {
0%,30% {opacity: 0;-mo...
两种js滑动门(tab切换)效果 - 源码下载 - 清泛网 - 专注C/C++及内核技术
... tab切换 效果源码如下：<!DOCTYPE html PUBLIC "- W3C DTD XHTML 1.0 Transitional EN" "http: www.w3.org TR xhtml1 DTD xhtml1-transition...
源码如下：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html...
How to check whether a pandas DataFrame is empty?
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505
You can use the attribute df.empty to check whether it's empty or not:
if df.empty:
print(...
SQL keys, MUL vs PRI vs UNI
...at column.
– pgoetz
Aug 7 '19 at 16:07
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What does the constant 0.0039215689 represent?
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0.0039215689 is approximately equal to 1/255.
Seeing that this is OpenGL, performance is probably important. So it's probably safe to guess that this was done for performance reasons.
Multiplying by the reciprocal is faster...