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Selecting/excluding sets of columns in pandas [duplicate]
...e to create views or dataframes from an existing dataframe based on column selections.
9 Answers
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Named capturing groups in JavaScript regex?
...if the order of the groups changes? Also, it's annonying to put this extra chars on the other groups...
– Alba Mendez
Nov 9 '12 at 15:45
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How to use SQL Order By statement to sort results case insensitive?
...You can just convert everything to lowercase for the purposes of sorting:
SELECT * FROM NOTES ORDER BY LOWER(title);
If you want to make sure that the uppercase ones still end up ahead of the lowercase ones, just add that as a secondary sort:
SELECT * FROM NOTES ORDER BY LOWER(title), title;
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Pipe to/from the clipboard in Bash script
...lets you talk to it.
In the case of X, there's xclip (and others). xclip -selection c will send data to the clipboard that works with Ctrl + C, Ctrl + V in most applications.
If you're on Mac OS X, there's pbcopy. e.g cat example.txt | pbcopy
If you're in Linux terminal mode (no X) then look into...
Convert pandas dataframe to NumPy array
...ution, in this case, to_numpy without explaining how to recover the column selecting functionality of as_matrix! I am sure there are other ways to select columns, but as_matrix was at least one of them!
– Jérémie
Jul 31 '19 at 23:50
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Event handler not working on dynamic content [duplicate]
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You have to add the selector parameter, otherwise the event is directly bound instead of delegated, which only works if the element already exists (so it doesn't work for dynamically loaded content).
See http://api.jquery.com/on/#direct-and-del...
MySQL “NOT IN” query
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To use IN, you must have a set, use this syntax instead:
SELECT * FROM Table1 WHERE Table1.principal NOT IN (SELECT principal FROM table2)
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How to list all the available keyspaces in Cassandra?
...keyspace in the system schema using the SQL query
below is the command.
SELECT * FROM system_schema.keyspaces;
Hope this will answer your question...
You can go through the explanation on understanding and creating the keyspaces from below resources.
Documentation:
https://docs.datastax.co...
Removing duplicate rows from table in Oracle
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Use the rowid pseudocolumn.
DELETE FROM your_table
WHERE rowid not in
(SELECT MIN(rowid)
FROM your_table
GROUP BY column1, column2, column3);
Where column1, column2, and column3 make up the identifying key for each record. You might list all your columns.
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typecast string to integer - Postgres
...ur value is an empty string, you can use NULLIF to replace it for a NULL:
SELECT
NULLIF(your_value, '')::int
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