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How to sort a list/tuple of lists/tuples by the element at a given index?
...
In order to sort a list of tuples (<word>, <count>), for count in descending order and word in alphabetical order:
data = [
('betty', 1),
('bought', 1),
('a', 1),
('bit', 1),
('of', 1),
('butter', 2),
('but', 1),
('...
How to sort a file, based on its numerical values for a field?
...614990234375
-0.907928466796875
1.135406494140625
Which is obviously not ordered by numeric value.
Then, I guess that a more precise answer would be to use sort -n but only if all the values are positive.
P.S.: Using sort -g returns just the same results for this example
Edit:
Looks like the l...
SQLAlchemy: What's the difference between flush() and commit()?
...the remote server. It turns out that due to the way sqlalchemy is written, order of operations when committing is not guaranteed. This resulted in adding a duplicate version (before attempting to delete the old one), which resulted in the DB failing a unique constraint. To get around this I used flu...
SQL Server CTE and recursion example
...loyees
WHERE EmployeeID = cteReports.MgrID) AS Manager
FROM cteReports
ORDER BY EmpLevel, MgrID
The simplest example of a recursive CTE I can think of to illustrate its operation is;
;WITH Numbers AS
(
SELECT n = 1
UNION ALL
SELECT n + 1
FROM Numbers
WHERE n+1 <= 10
)
S...
How can I select rows with most recent timestamp for each key value?
...SELECT MAX(timestamp) FROM sensorTable s2 WHERE s1.sensorID = s2.sensorID)
ORDER BY sensorID, timestamp;
Pretty self-explaining I think, but here's more info if you wish, as well as other examples. It's from the MySQL manual, but above query works with every RDBMS (implementing the sql'92 standard...
Rank items in an array using Python/NumPy, without sorting array twice
...
Use argsort twice, first to obtain the order of the array, then to obtain ranking:
array = numpy.array([4,2,7,1])
order = array.argsort()
ranks = order.argsort()
When dealing with 2D (or higher dimensional) arrays, be sure to pass an axis argument to argsort to...
How to attach javadoc or sources to jars in libs folder?
...ers from Xavier, plastiv, VinceFR and Christopher.
Step by step guide
In order to link the sources and javadoc to a .jar library that is automatically linked by Eclipse you have to do the following:
Place the library .jar file in the libs folder, and the associated source .jar and doc .jar files...
Entity Framework Code First - two Foreign Keys from same table
...
public int MatchId { get; set; }
[ForeignKey("HomeTeam"), Column(Order = 0)]
public int? HomeTeamId { get; set; }
[ForeignKey("GuestTeam"), Column(Order = 1)]
public int? GuestTeamId { get; set; }
public float HomePoints { get; set; }
public float GuestPoints { get; se...
Difference between partition key, composite key and clustering key in Cassandra?
...tition key columns, then you can add optionally each clustering key in the order they're set.
so the valid queries are (excluding secondary indexes)
col1 and col2
col1 and col2 and col10
col1 and col2 and col10 and col 4
Invalid:
col1 and col2 and col4
anything that does not contain both col1...
Composite Key with EF 4.1 Code First
...uld work - composite key defined with annotations requires explicit column order:
public class ActivityType
{
[Key, Column(Order = 0)]
public int ActivityID { get; set; }
[Key, Column(Order = 1)]
[Required(ErrorMessage = "A ActivityName is required")]
[StringLength(50, ErrorMes...