大约有 43,000 项符合查询结果（耗时：0.0410秒） [XML]
Frequency table for a single variable
... the columns as such
[my_series[c].value_counts() for c in list(my_series.select_dtypes(include=['O']).columns)]
Breakdown:
my_series.select_dtypes(include=['O'])
Selects just the categorical data
list(my_series.select_dtypes(include=['O']).columns)
Turns the columns f...
Is there a MySQL option/feature to track history of changes to records?
...i AFTER INSERT ON MyDB.data FOR EACH ROW
INSERT INTO MyDB.data_history SELECT 'insert', NULL, NOW(), d.*
FROM MyDB.data AS d WHERE d.primary_key_column = NEW.primary_key_column;
CREATE TRIGGER MyDB.data__au AFTER UPDATE ON MyDB.data FOR EACH ROW
INSERT INTO MyDB.data_history SELECT 'up...
Unix command-line JSON parser? [closed]
... you to do powerful things really easily:
cat earthporn.json | underscore select '.data .title'
# [ 'Fjaðrárgljúfur canyon, Iceland [OC] [683x1024]',
# 'New town, Edinburgh, Scotland [4320 x 3240]',
# 'Sunrise in Bryce Canyon, UT [1120x700] [OC]',
# ...
# 'Kariega Game Reserve, South Afric...
Move entire line up and down in Vim
...;A-down> but when I try those keys in vim in visual running in tmux the selection disappears and the cursor moves line up; without moving the selected lines.
– Konrad
Dec 27 '16 at 9:49
...
How to write a simple Html.DropDownListFor()?
...%= Html.DropDownListFor(n => n.MyColorId,
new SelectList(Colors, "ColorId", "Name")) %>
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Android Studio IDE: Break on Exception
...s.
The Breakpoints dialog appears. In the left pane, scroll to the bottom. Select Any exception under Java Exception Breakpoints
With Any exception selected, on the right pane, configure as follows:
Suspend: checked
All: selected
Condition: !(this instanceof java.lang.ClassNotFoundException)
Noti...
MySQL/Amazon RDS error: “you do not have SUPER privileges…”
...e “Parameter Groups” tab.
Create a new Parameter Group. On the dialog, select the MySQL family compatible to your MySQL database version, give it a name and confirm.
Select the just created Parameter Group and issue “Edit Parameters”.
Look for the parameter ‘log_bin_trust_function_creators...
How to stop a goroutine
...a signal, it quits.
quit := make(chan bool)
go func() {
for {
select {
case <- quit:
return
default:
// Do other stuff
}
}
}()
// Do stuff
// Quit goroutine
quit <- true
...
Visual Studio 2013 Missing Convert To Web Application
...
It's been moved to the 'Project' menu towards the bottom after selecting the project or folder:
Sources: http://connect.microsoft.com/VisualStudio/feedback/details/806246/visual-studio-2013-web-forms-conver-to-web-applications
...
SQL Server IN vs. EXISTS Performance
...execution operation, to get their results.
An example:
Query 1 ( plan )
select * from dt where dt.customer in (select c.code from customer c where c.active=0)
Query 2 ( plan )
select * from dt where exists (select 1 from customer c where c.code=dt.customer and c.active=0)
...