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Convert pandas dataframe to NumPy array
...taining NumPy arrays from pandas objects:
to_numpy(), which is defined on Index, Series, and DataFrame objects, and
array, which is defined on Index and Series objects only.
If you visit the v0.24 docs for .values, you will see a big red warning that says:
Warning: We recommend using DataFrame.to...
Replace only some groups with Regex
... var currentCaptureEnd =
capture.Index + capture.Length - m.Index;
var currentCaptureLength =
capture.Index - m.Index - previousCaptureEnd;
sb.Append(
m.Value.Substring(
...
Delete all documents from index/type without deleting type
...option will delete the type and its mappings. So don't forget to remap the index type after deleting. Or else you will be messed up.
– Finny Abraham
Sep 15 '15 at 6:14
24
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What's the difference between require and require-dev? [duplicate]
...roduction version of your project.
Typically, these are packages such as phpunit/phpunit that you would only use during development.
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Select first row in each GROUP BY group?
...otal can be NULL (won't hurt either way, but you'll want to match existing indexes):
...
ORDER BY customer, total DESC NULLS LAST, id;
Major points
DISTINCT ON is a PostgreSQL extension of the standard (where only DISTINCT on the whole SELECT list is defined).
List any number of expressions in the ...
Does PostgreSQL support “accent insensitive” collations?
...eded).
SELECT *
FROM users
WHERE unaccent(name) = unaccent('João');
Index
To use an index for that kind of query, create an index on the expression. However, Postgres only accepts IMMUTABLE functions for indexes. If a function can return a different result for the same input, the index could...
Selecting multiple columns in a pandas dataframe
..._ syntax (the []'s).
df1 = df[['a', 'b']]
Alternatively, if it matters to index them numerically and not by their name (say your code should automatically do this without knowing the names of the first two columns) then you can do this instead:
df1 = df.iloc[:, 0:2] # Remember that Python does not ...
How to get the index of an element in an IEnumerable?
...ily iterate over the contents. As such, there isn't really a concept of an index. What you are doing really doesn't make a lot of sense for an IEnumerable. If you need something that supports access by index, put it in an actual list or collection.
...
How to get index of object by its property in JavaScript?
...turn -1 when not found so it follows the same construct as Array.prototype.indexOf()
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PDO's query vs execute
...ause I was bulk transferring trusted data from an Ubuntu Linux box running PHP7 with the poorly supported Microsoft ODBC driver for MS SQL Server.
I arrived at this question because I had a long running script for an ETL that I was trying to squeeze for speed. It seemed intuitive to me that query c...