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Look up all descendants of a class in Ruby
...e:
class Parent
def self.descendants
ObjectSpace.each_object(Class).select { |klass| klass < self }
end
end
class Child < Parent
end
class GrandChild < Child
end
puts Parent.descendants
puts Child.descendants
puts Parent.descendants gives you:
GrandChild
Child
puts Child.de...
Subversion stuck due to “previous operation has not finished”?
...ading SQLite to my checkout directory and running
sqlite3.exe .svn/wc.db "select * from work_queue"
you can get a list of all pending operations. These operations are the ones the error is referring to as "not finished".
By running
sqlite3.exe .svn/wc.db "delete from work_queue"
all of the o...
Alternate table row color using CSS?
.../td>
</tr>
</tbody>
</table>
There is a CSS selector, really a pseudo-selector, called nth-child. In pure CSS you can do the following:
tr:nth-child(even) {
background-color: #000000;
}
Note: No support in IE 8.
Or, if you have jQuery:
$(document).ready(functi...
How To Capture A Minidump: Let Me Count The Ways - C/C++ - 清泛网 - 专注C/C++及内核技术
... in the Applications or the Processes tabs, right click on the process and select Create Dump File.
After the minidump is finished, you’ll see the dialog showing you where the dump was created. A nice hidden treat is that the path shown is a read only edit control you can select and copy so...
How to fix error “Updating Maven Project”. Unsupported IClasspathEntry kind=4?
...
Right-click on your project, select Maven -> Remove Maven Nature.
Open you terminal, go to your project folder and do mvn eclipse:clean
Right click on your Project and select “Configure -> Convert into Maven Project”
Now you got “Unsupporte...
How to make ruler always be shown in Sublime text 2?
...
As others have stated before me, select Preferences -> Settings-User and change
"rulers": [],
to
"rulers": [80],
in order to display one ruler at column 80.
Now for the rub, it seems that one must use a monospaced font in order to display rulers so y...
Inserting a Python datetime.datetime object into MySQL
...
when iserting into t-sql
this fails:
select CONVERT(datetime,'2019-09-13 09:04:35.823312',21)
this works:
select CONVERT(datetime,'2019-09-13 09:04:35.823',21)
easy way:
regexp = re.compile(r'\.(\d{6})')
def to_splunk_iso(dt):
"""Converts the datetime ...
Cannot open backup device. Operating System error 5
...
Go to the SQL server folder in start menu and click configuration tools
Select SQL Server configuration manager
On SQL server services, on the desired instance change the (Log On as) to local system
share
|
...
Swift Bridging Header import issue
...roblem:
1. Delete all your bridging files that you created until now.
2. Select the main folder of project and hit new file->iOS->Header file.
3. Write your imports in the header file created.
4. Select the project inside Xcode->Build Settings, type in search field: bridging and put in ...
Pass a data.frame column name to a function
...(x[,column])
}
fun1(df, "B", max)
Alternatively, using [[ also works for selecting a single column at a time:
df <- data.frame(A=1:10, B=2:11, C=3:12)
fun1 <- function(x, column){
max(x[[column]])
}
fun1(df, "B")
...