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Is an index needed for a primary key in SQLite?
...x be explicitly created for it as well? SQLite does not appear to automatically create an index for a primary key column, but perhaps it indexes it anyway, given its purpose? (I will be searching on that column all the time).
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Converting a Pandas GroupBy output from Series to DataFrame
...1.index
Out[20]:
MultiIndex([('Alice', 'Seattle'), ('Bob', 'Seattle'), ('Mallory', 'Portland'),
('Mallory', 'Seattle')], dtype=object)
Perhaps you want something like this?
In [21]: g1.add_suffix('_Count').reset_index()
Out[21]:
Name City City_Count Name_Count
0 Alice S...
sqlalchemy IS NOT NULL select
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column_obj != None will produce a IS NOT NULL constraint:
In a column context, produces the clause a != b. If the target is None, produces a IS NOT NULL.
or use isnot() (new in 0.7.9):
Implement the IS NOT operator.
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How to define @Value as optional
...swered Jan 8 '18 at 13:23
alonso_50alonso_50
9941010 silver badges1515 bronze badges
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Duplicate headers received from server
...invalidChars);
string replace = Regex.Replace(name, invalidReStr, "_").Replace(";", "").Replace(",", "");
return replace;
}
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Jasmine.js comparing arrays
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this falls back on "==" in javascript by default. This is just not safe since not only the actual values are compared, but the whole object.
– Peter
Nov 12 '14 at 11:00
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Shorten string without cutting words in JavaScript
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Lodash has a function specifically written for this: _.truncate
const truncate = _.truncate
const str = 'The quick brown fox jumps over the lazy dog'
truncate(str, {
length: 30, // maximum 30 characters
separator: /,?\.* +/ // separate by spaces, including preceding comma...
Difference between this and self in self-type annotations?
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All three forms are valid, and have the effect that B is assumed as the type of this in class A.
The first two variants
trait A { self: B => ... }
trait A { foo: B => ... }
introduce self (respectively, foo) as an ...
Differences between utf8 and latin1
... at least 5.5 or go for another RDBMS like PostgreSQL. In MySQL 5.5+ it's called utf8mb4.
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Cannot create an array of LinkedLists in Java…?
...nto it. ArrayList will index faster, but Fredrik's solution is better overall.
– Steve Zobell
Mar 9 '17 at 20:08
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