大约有 47,000 项符合查询结果（耗时：0.0298秒） [XML]
How to take column-slices of dataframe in pandas
...e .loc
See the deprecation in the docs
.loc uses label based indexing to select both rows and columns. The labels being the values of the index or the columns. Slicing with .loc includes the last element.
Let's assume we have a DataFrame with the following columns:
foo, bar, quz, ant, cat, ...
What CSS selector can be used to select the first div within another div
...
Can you tell me how to select all div except first/last div?
– Tân
Jul 5 '16 at 9:17
5
...
Difference between timestamps with/without time zone in PostgreSQL
...inations of those factors:
foo=> SET TIMEZONE TO 'Japan';
SET
foo=> SELECT '2011-01-01 00:00:00'::TIMESTAMP;
timestamp
---------------------
2011-01-01 00:00:00
(1 row)
foo=> SELECT '2011-01-01 00:00:00'::TIMESTAMP WITH TIME ZONE;
timestamptz
--------------------...
How do I create a new class in IntelliJ without using the mouse?
...with arrow keys, then press Alt+Insert.
Another useful shortcut is View | Select In (Alt+F1), Project (1), then Alt+Insert to create a class near the existing one or use arrow keys to navigate through the packages.
And yet another way is to just type the class name in the existing code where you w...
iphone: Where the .dSYM file is located in crash report
...
You can locate .dSYM and application binary file in archive.
Select Window -> Organizer
This will open up Organizer window containing last created Archive of project
Right click on Archive and select 'Show in Finder'
Select 'Show Package Content' for archive
Project.xcarchive...
PostgreSQL LIKE query performance variations
... gist_trgm_ops);
Difference between GiST and GIN index
Example query:
SELECT * FROM tbl WHERE col LIKE '%foo%'; -- leading wildcard
SELECT * FROM tbl WHERE col ILIKE '%foo%'; -- works case insensitively as well
Trigrams? What about shorter strings?
Words with less than 3 letters in indexed...
How to update column with null value
...Hello');
UPDATE your_table
SET your_column = NULL
WHERE some_id = 1;
SELECT * FROM your_table WHERE your_column IS NULL;
+---------+-------------+
| some_id | your_column |
+---------+-------------+
| 1 | NULL |
+---------+-------------+
1 row in set (0.00 sec)
...
JavaScript get clipboard data on paste event (Cross browser)
...vent using a keypress event handler
In that handler, save the current user selection, add a textarea element off-screen (say at left -1000px) to the document, turn designMode off and call focus() on the textarea, thus moving the caret and effectively redirecting the paste
Set a very brief timer (say...
Android studio add external project to build.gradle
...ick module -> Open Module Settings -> Dependencies -> + (bottom), select Module Dependency, select your library from the list, click ok :)
– T.Coutlakis
Jan 11 '15 at 22:51
...
How to drop a table if it exists?
...
Is it correct to do the following?
IF EXISTS(SELECT *
FROM dbo.Scores)
DROP TABLE dbo.Scores
No. That will drop the table only if it contains any rows (and will raise an error if the table does not exist).
Instead, for a permanent table you can use
I...