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Python Pandas merge only certain columns
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You can use .loc to select the specific columns with all rows and then pull that. An example is below:
pandas.merge(dataframe1, dataframe2.iloc[:, [0:5]], how='left', on='key')
In this example, you are merging dataframe1 and dataframe2. You h...
How to determine why visual studio might be skipping projects when building a solution
...tion Explorer, right-click the solution > Add > Existing Project and select your project
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Rails find record with zero has_many records associated [duplicate]
..._joins(:photos).where(photos: {id: nil})
which will result in SQL like:
SELECT cities.*
FROM cities LEFT OUTER JOIN photos ON photos.city_id = city.id
WHERE photos.id IS NULL
Using includes:
City.includes(:photos).where(photos: {id: nil})
will have the same result, but will result in much ug...
How to get a one-dimensional scalar array as a doctrine dql query result?
...as callback, instead of writing a closure.
$result = $em->createQuery("SELECT a.id FROM Auction a")->getScalarResult();
$ids = array_map('current', $result);
See Petr Sobotka's answer below for additional info regarding memory usage.
PHP >= 5.5
As jcbwlkr's answered below, the rec...
Intellij shortcut to convert code to upper or lower case?
... I have trouble where sometimes pressing CTRL+SHIFT+U just replaces the selected text with the letter U.... sometimes it works, but usually it just does the replacing.
– Trenton
Jul 31 '14 at 16:15
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How exactly does __attribute__((constructor)) work?
...unction call to any of the functions declared above
*/
int
main (int argc, char *argv[]) {
printf ("\n\t [ main body of program ]\n");
return 0;
}
output:
init_some_function() called by elf_init()
elf_init() -- (.section .init)
construct1() constructor -- (.section .ctors) pr...
Is there a shortcut to make a block comment in Xcode?
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Created Automator service using AppleScript
Make sure "Output replaces selected text" is checked
Enter the following code:
on run {input, parameters}
return "/*\n" & (input as string) & "*/"
end run
Now you can access that service through Xcode - Services menu, or by right clicking...
How to set the java.library.path from Eclipse
... has items for source/javadoc and native library locations.
Specifically: select Project, right click -> Properties / Java Build Path / Libraries tab, select a .jar, expand it, select Native library location, click Edit, folder chooser dialog will appear)
Messing with the library path on the co...
Oracle 11.2.0.4 RAC FOR redhat 6.4 - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
...nolog
SQL> conn / as sysdba
SQL> startup
查看数据库状态
SQL> select open_mode from v$database;
OPEN_MODE
--------------------
READ WRITE
查看数据库字符集
SQL> select userenv('language') from dual;
SQL> select * from props$ where name='NLS_CHARACTERSET';
SQL> select * ...
Drop columns whose name contains a specific string from pandas DataFrame
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Use the DataFrame.select method:
In [38]: df = DataFrame({'Test1': randn(10), 'Test2': randn(10), 'awesome': randn(10)})
In [39]: df.select(lambda x: not re.search('Test\d+', x), axis=1)
Out[39]:
awesome
0 1.215
1 1.247
2 0.142
3...