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Convert columns to string in Pandas
...cated dtype.
object dtype breaks dtype-specific operations like DataFrame.select_dtypes(). There isn’t a clear way to select just text
while excluding non-text but still object-dtype columns.
When reading code, the contents of an object dtype array is less clear than 'string'.
See also the se...
How to get disk capacity and free space of remote computer
...t Win32_LogicalDisk -ComputerName remotecomputer -Filter "DeviceID='C:'" |
Select-Object Size,FreeSpace
$disk.Size
$disk.FreeSpace
To extract the values only and assign them to a variable:
$disk = Get-WmiObject Win32_LogicalDisk -ComputerName remotecomputer -Filter "DeviceID='C:'" |
Foreach-Obje...
LEFT JOIN vs. LEFT OUTER JOIN in SQL Server
...default is INNER if you just specify JOIN. In other words, this is legal:
SELECT *
FROM A JOIN B ON A.X = B.Y
Here's a list of equivalent syntaxes:
A LEFT JOIN B A LEFT OUTER JOIN B
A RIGHT JOIN B A RIGHT OUTER JOIN B
A FULL JOIN B A FULL OUTER JOIN B
A INNER JOIN...
Code-first vs Model/Database-first [closed]
...In fact, I still write a lot of stored procedures for the more high volume select statements and such, and then I'll do a function import into the EF model all in the name of performance.
– Steve Wortham
Jun 14 '11 at 14:36
...
How to add 'ON DELETE CASCADE' in ALTER TABLE statement
...ARE
CURSOR consCols (theCons VARCHAR2, theOwner VARCHAR2) IS
select * from user_cons_columns
where constraint_name = theCons and owner = theOwner
order by position;
firstCol BOOLEAN := TRUE;
begin
-- For each constraint
FOR cons IN (sel...
How To Auto-Format / Indent XML/HTML in Notepad++
...extFX as a plugin. Plugins -> Plugin Manager -> Show Plugin Manager. Select TextFX and install. After a restart of npp, the menu 'TextFS' should be visible.
– remipod
Mar 5 '12 at 8:59
...
内存优化总结:ptmalloc、tcmalloc和jemalloc - 操作系统(内核) - 清泛网 - ...
... 总共32个vcpu。 16个table，每个5M row。
OLTP_RO测试包含5个select查询：select_ranges, select_order_ranges, select_distinct_ranges, select_sum_ranges,
可以看到在多核心或者多线程的场景下， jemalloc和tcmalloc带来的tps增加非常明显。
参考资料
glibc...
Can't find a “not equal” css attribute selector
...
One problem with the accepted answer is that it will also select elements that do not have a foo attribute at all. Consider:
<div>No foo</div>
<div foo="">Empty foo</div>
<div foo="x">XXX</div>
<div foo="y">YYY</div>
<div foo="z"&g...
SQL - The conversion of a varchar data type to a datetime data type resulted in an out-of-range valu
...table). In comment you said you want it in yyyy-mm-dd format. So, try this SELECT CONVERT(char(10), GetDate(),126). Just replace GETDATE() with necessary value.
– Mahe
Dec 30 '13 at 15:29
...
How to change checkbox's border style in CSS?
...
outline is very good, and it works for all input and select boxes, making this useful for ".error" classes.
– SztupY
Oct 3 '11 at 14:42
2
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