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How do I choose between Semaphore and SemaphoreSlim?
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From the MSDN documentation, "The SemaphoreSlim class is the recommended semaphore for synchronization within a single app.". Except for special cases, you should default to using SemaphoreSlim if only one process is using th...
How to save as a new file and keep working on the original one in Vim?
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From Vim's help: :sav[eas][!] [++opt] {file} So, :sav is the shortener for :saveas. Whereas, :w is the shortcut for :[range]w[rite][!] [++opt] {file}. And everything is in the manual, just few lines above/below.
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Dictionary vs Object - which is more efficient and why?
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Have you tried using __slots__?
From the documentation:
By default, instances of both old and new-style classes have a dictionary for attribute storage. This wastes space for objects having very few instance variables. The space consumption can become acut...
How do I keep the screen on in my App? [duplicate]
For my Android app I never want the phone to lock or the back light to turn off
11 Answers
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LISTAGG in Oracle to return distinct values
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19c and later:
select listagg(distinct the_column, ',') within group (order by the_column)
from the_table
18c and earlier:
select listagg(the_column, ',') within group (order by the_column)
from (
select distinct the_column
from t...
Best way to test if a row exists in a MySQL table
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You could also try EXISTS:
SELECT EXISTS(SELECT * FROM table1 WHERE ...)
and per the documentation, you can SELECT anything.
Traditionally, an EXISTS subquery starts with SELECT *, but it could
begin with SELECT 5 or SELECT column1 or anything ...
Convert a String representation of a Dictionary to a dictionary?
... literal structures: strings, numbers, tuples, lists, dicts, booleans,
and None.
For example:
>>> eval("shutil.rmtree('mongo')")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<string>", line 1, in <module>
File "/opt/Python...
How to filter SQL results in a has-many-through relation
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Results:
Total runtimes from EXPLAIN ANALYZE.
1) Martin 2: 44.594 ms
SELECT s.stud_id, s.name
FROM student s
JOIN student_club sc USING (stud_id)
WHERE sc.club_id IN (30, 50)
GROUP BY 1,2
HAVING COUNT(*) > 1;
2) Erwin 1: 33.217 ms
SELECT s.stud_id, s.name
FROM student s
JOIN ...
How can I select from list of values in SQL Server
... would be to use a find an replace with UNION to get the distinct values.
SELECT 1
UNION SELECT 1
UNION SELECT 1
UNION SELECT 2
UNION SELECT 5
UNION SELECT 1
UNION SELECT 6
Applied to your long line of comma delimited text
Find and replace every comma with UNION SELECT
Add a SELECT in front of ...
Is HTML considered a programming language? [closed]
...ring whether HTML qualifies as a programming language (obviously the "L" stands for language).
15 Answers
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