大约有 15,000 项符合查询结果（耗时：0.0304秒） [XML]
SQLAlchemy ORDER BY DESCENDING?
...
from sqlalchemy import desc
someselect.order_by(desc(table1.mycol))
Usage from @jpmc26
share
|
improve this answer
|
follow
...
Show an image preview before upload
... code snippet in the HTML example below filters out images from the user's selection and renders selected files into multiple thumbnail previews:
function handleFileSelect(evt) {
var files = evt.target.files;
// Loop through the FileList and render image files as thumbnails.
fo...
Concat all strings inside a List using LINQ
....Boo);
Console.ReadKey();
}
}
And here is my best :)
items.Select(i => i.Boo).Aggregate((i, j) => i + delimiter + j)
share
|
improve this answer
|
foll...
Get PostGIS version
...s like GEOS and proj4 you might want to get their versions too. Then use:
SELECT PostGIS_full_version();
share
|
improve this answer
|
follow
|
...
Block commenting in Ruby
...
In TextMate, you can alt-drag vertically to select a column of text. This will duplicate the insertion point across all the lines you select, so you can insert or delete multiple #s at once.
UPDATE: Also in TextMate, assuming you have the right language selected, Cmd ...
Using awk to remove the Byte-order mark
...
In addition to converting CRLF line endings to LF, dos2unix also removes BOMs:
dos2unix *.txt
dos2unix also converts UTF-16 files with a BOM (but not UTF-16 files without a BOM) to UTF-8 without a BOM:
$ printf '\ufeffä\n'|iconv -f utf...
When do you use map vs flatMap in RxJava?
... in RxJava?. And I think a simple demo is more specific.
When you want to convert item emitted to another type , in your case converting file to String, map and flatMap can both work. But I prefer map operator because it's more clearly.
However in some place, flatMap can do magic work but map can'...
Case conventions on element names?
...inent examples:
<a>1</a><b>1</b>
<xsl:value-of select="a+b"/>
outputs 2, as expected
<a>1</a><b>1</b>
<xsl:value-of select="a-b"/>
DOES NOT ERROR, BUT OUTPUTS NOTHING AT ALL
In the above code, you must put at least one space before a su...
Why does changing the sum order returns a different result?
...ory, floating points use a special format along the lines of IEEE 754 (the converter provides much better explanation than I can).
Anyways, here's the float converter.
http://www.h-schmidt.net/FloatConverter/
The thing about the order of operations is the "fineness" of the operation.
Your first ...
Smooth GPS data
...n be ignored, because if you put scaling factors into the Kalman filter to convert them all into the same units, then those scaling factors end up cancelling out when converting the results back into the original units.
The code could be improved, because it assumes that the best estimate of curren...