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Pandas dataframe get first row of each group
...column:
>>> df.groupby('id').first().reset_index()
id value
0 1 first
1 2 first
2 3 first
3 4 second
4 5 first
5 6 first
6 7 fourth
To get n first records, you can use head():
>>> df.groupby('id').head(2).reset_index(drop=True)
id value
0 ...
Is there any “font smoothing” in Google Chrome?
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Status of the issue, June 2014: Fixed with Chrome 37
Finally, the Chrome team will release a fix for this issue with Chrome 37 which will be released to public in July 2014. See example comparison of current stable Chrome 35 and latest Chrome 37 (earl...
.NET Global exception handler in console application
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edited May 29 '18 at 14:05
answered Jun 28 '10 at 14:32
H...
Is < faster than
Is if( a &lt; 901 ) faster than if( a &lt;= 900 ) .
14 Answers
14
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“x not in y” or “not x in y”
... 'ham' not in 'spam and eggs'
&gt;&gt;&gt; dis.dis(notin)
2 0 LOAD_CONST 1 ('ham')
3 LOAD_CONST 2 ('spam and eggs')
6 COMPARE_OP 7 (not in)
9 POP_TOP
10 LOAD_CONST ...
How to split a sequence into two pieces by predicate?
...ing partition method:
scala&gt; List(1,2,3,4).partition(x =&gt; x % 2 == 0)
res0: (List[Int], List[Int]) = (List(2, 4),List(1, 3))
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Running a cron job at 2:30 AM everyday
How to configure a cron job to run every night at 2:30? I know how to make it run at 2, but not 2:30.
6 Answers
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Email validation using jQuery
...ld javascript for that:
function isEmail(email) {
var regex = /^([a-zA-Z0-9_.+-])+\@(([a-zA-Z0-9-])+\.)+([a-zA-Z0-9]{2,4})+$/;
return regex.test(email);
}
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How to install Java SDK on CentOS?
...n you read this, the lastest available version may be different.
java-1.7.0-openjdk.x86_64
The above package alone will only install JRE. To also install javac and JDK, the following command will do the trick:
$ yum install java-1.7.0-openjdk*
These packages will be installing (as well as thei...
Maintaining the final state at end of a CSS3 animation
I'm running an animation on some elements that are set to opacity: 0; in the CSS. The animation class is applied onClick, and, using keyframes, it changes the opacity from 0 to 1 (among other things).
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