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python pandas remove duplicate columns
...,False,True].
Pandas allows one to index using boolean values whereby it selects only the True values. Since we want to keep the unduplicated columns, we need the above boolean array to be flipped (ie [True, True, False] = ~[False,False,True])
Finally, df.loc[:,[True,True,False]] selects only the...
How can I prevent SQL injection in PHP?
...
Using PDO (for any supported database driver):
$stmt = $pdo->prepare('SELECT * FROM employees WHERE name = :name');
$stmt->execute([ 'name' => $name ]);
foreach ($stmt as $row) {
// Do something with $row
}
Using MySQLi (for MySQL):
$stmt = $dbConnection->prepare('SELECT * FROM...
How can I set the PHP version in PHPStorm?
...ndows:
File -> Settings -> Languages & Frameworks > PHP
then select your PHP version, for example, 7.0
This is very useful when your local system runs PHP 7.0, for example, but production is running PHP 5.5.
That way PhpStorm will warn you which parts will not work in production, show ...
What is a NullReferenceException, and how do I fix it?
... to find out where the reference is or isn't set, right-click its name and select "Find All References". You can then place a breakpoint at every found location and run your program with the debugger attached. Every time the debugger breaks on such a breakpoint, you need to determine whether you exp...
jQuery OR Selector?
I am wondering if there is a way to have "OR" logic in jQuery selectors. For example, I know an element is either a descendant of an element with class classA or classB, and I want to do something like elem.parents('.classA or .classB') . Does jQuery provide such functionality?
...
Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
...ata.frame(a = 1:3, b=letters[1:3])
require(sqldf)
a1NotIna2 <- sqldf('SELECT * FROM a1 EXCEPT SELECT * FROM a2')
And the rows which are in both data frames:
a1Ina2 <- sqldf('SELECT * FROM a1 INTERSECT SELECT * FROM a2')
The new version of dplyr has a function, anti_join, for exactly the...
Pushing from local repository to GitHub hosted remote
... my GIT version 1.8.4:
From the local repository folder, right click and select 'Git Commit Tool'.
There, select the files you want to upload, under 'Unstaged Changes' and click 'Stage Changed' button. (You can initially click on 'Rescan' button to check what files are modified and not uploaded ye...
SQL Server 2008 can't login with newly created user
...ick on SQL Server instance at root of Object Explorer, click on Properties
Select Security from the left pane.
Select the SQL Server and Windows Authentication mode radio button, and click OK.
Right-click on the SQL Server instance, select Restart (alternatively, open up Services and restart the ...
Provisioning Profiles menu item missing from Xcode 5
...nage your profiles (mostly to clean up):
Open Windows/Devices in Xcode 6
Select your device
Show Provisioning Profiles:
You'll get + and - buttons to add/remove profiles:
No longer supported ... you can also download Apple's iPhone Configuration Utility 3.5 for Mac OS X, it still has "Provis...
关于php的socket初探 - PHP - 清泛IT论坛，有思想、有深度
...连接的模型都应该被称为多路复用，目前比较常用的有 select/poll/epoll/kqueue 这些 IO 模型（目前也有像 Apache 这种每个连接用单独的进程/线程来处理的 IO 模型，但是效率相对比较差，也很容易出问题，所以暂时不做介绍了）。在...