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Is it safe to remove selected keys from map within a range loop?
How can one remove selected keys from a map?
Is it safe to combine delete() with range, as in the code below?
4 Answers
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What does the “>” (greater-than sign) CSS selector mean?
...etimes mistakenly called the direct descendant combinator.1
That means the selector div > p.some_class only selects paragraphs of .some_class that are nested directly inside a div, and not any paragraphs that are nested further within.
An illustration:
div > p.some_class {
background:...
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
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Convert a string to int using sql query
...
You could use CAST or CONVERT:
SELECT CAST(MyVarcharCol AS INT) FROM Table
SELECT CONVERT(INT, MyVarcharCol) FROM Table
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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...
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
--------------------...
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...
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)
...
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...