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Use a list of values to select rows from a pandas dataframe [duplicate]
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How would you return these values in the order of the list? For example, list_of_values has values 3 then 6 but the frame is returned with 6 then 3. I'm not talking about a simple sort, rather how specifically can we return in the order of the values in the list.
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When do we have to use copy constructors?
...ly, this is cached/memoized data accumulated over the object's lifetime in order to speed-up certain slow query operations performed by the object. It is safe to skip copying that data since it will be recalculated when (and if!) the relevant operations are performed. Copying this data may be unjust...
How to install Java SDK on CentOS?
... After Installation: configuring iptables on centos 6.5 -> /etc/sysconfig/iptables -> -A INPUT -i eth0 -p tcp -m tcp --dport 8080 -m state --state NEW,ESTABLISHED -j ACCEPT
– hpaknia
Jan 18 '15 at 11:17
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How do I create a crontab through a script
... used to control different cron tasks (control-marker-1, control-marker-2, etc...): (crontab -l 2>/dev/null | grep -v control-marker-1; echo '*/5 * * * * /path/to/job -with args #control-marker-1') | crontab -
– chef
Dec 25 '16 at 10:39
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What are the differences between B trees and B+ trees?
... fit on a page of memory. Therefore, it will require fewer cache misses in order to access data that is on a leaf node.
The leaf nodes of B+ trees are linked, so doing a full scan of all objects in a tree requires just one linear pass through all the leaf nodes. A B tree, on the other hand, would re...
Running PostgreSQL in memory only
...ils from a properties file, build target properties, environment variable, etc.
It's safe to use an existing PostgreSQL instance you already have databases you care about in, so long as the user you supply to your unit tests is not a superuser, only a user with CREATEDB rights. At worst you'll crea...
How do you determine what SQL Tables have an identity column programmatically
...RTY(object_id(TABLE_SCHEMA+'.'+TABLE_NAME), COLUMN_NAME, 'IsIdentity') = 1
order by TABLE_NAME
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Multiple arguments vs. options object
...plicated. If one of them relies on the others, so that they have a certain order (e.g. the fourth one needs the third one), you still should use multiple arguments. Nearly all native EcmaScript and DOM-methods work like this. A good example is the open method of XMLHTTPrequests, where the last 3 arg...
How to automatically start a service when running a docker container?
... @KarlMorrison docker exec -it <CONTAINER NAME> mysql /etc/init.d/mysqld restart
– kaiser
Mar 14 '16 at 0:46
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How to use GROUP_CONCAT in a CONCAT in MySQL
...B', 8);
INSERT INTO test VALUES (2, 'C', 9);
SELECT ID, GROUP_CONCAT(NAME ORDER BY NAME ASC SEPARATOR ',')
FROM (
SELECT ID, CONCAT(NAME, ':', GROUP_CONCAT(VALUE ORDER BY VALUE ASC SEPARATOR ',')) AS NAME
FROM test
GROUP BY ID, NAME
) AS A
GROUP BY ID;
SQL Fiddle: http://sqlfiddle.com/#!2/b...