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What is the difference between pluck and collect in Rails?
...ds with Rails 4, still use pluck
if you need some fields with Rails 3, use selectand collect
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what is the most efficient way of counting occurrences in pandas?
...].astype('str').stack().value_counts().sum() which equates to setting each selected column to str type, stacking all individual columns on top, forming basically one column and then doing the value_counts() and sum() on that one column. :) Stack is pretty useful, it might not be the most obvious cho...
MySQL主从服务器数据一致性的核对与修复 - 数据库(内核) - 清泛网 - 专注C/...
...保存到哪个库和表中，如果你愿意，可以手动查询：
SELECT db, tbl, SUM(this_cnt) AS total_rows, COUNT(*) AS chunks
FROM percona.checksums
WHERE (
master_cnt <> this_cnt
OR master_crc <> this_crc
OR ISNULL(master_crc) <> ISNULL(this_crc))
GROUP BY db, tbl;
BTW...
Django Rest Framework: Dynamically return subset of fields
...y parameter to a Django Rest Framework based API which enables the user to select only a subset of fields per resource.
8 A...
Alter Table Add Column Syntax
...order). Also, if there is data in the Employees table, it has to do insert select * so it can calculate the EmployeeID.
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Disable assertions in Python
...d allow assert statements to be optimized away is by raising them within a selection statement:
if foo_is_broken():
raise AssertionError('Foo is broken!')
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How to remove a file from the index in git?
...es in and out of the index by point-and-click. They even have support for selecting and moving portions of a file (individual changes) to and from the index.
How about a different perspective: If you mess up while using one of the suggested, rather cryptic, commands:
git rm --cached [file]
gi...
Force Java timezone as GMT/UTC
...
tl;dr
String sql = "SELECT CURRENT_TIMESTAMP ;
…
OffsetDateTime odt = myResultSet.getObject( 1 , OffsetDateTime.class ) ;
Avoid depending on host OS or JVM for default time zone
I recommend you write all your code to explicitly state the de...
How do I time a method's execution in Java?
....stop());
The nice thing is that Stopwatch.toString() does a good job of selecting time units for the measurement. I.e. if the value is small, it'll output 38 ns, if it's long, it'll show 5m 3s
Even nicer:
Stopwatch timer = Stopwatch.createUnstarted();
for (...) {
timer.start();
methodToTr...
Localization of DisplayNameAttribute
...
var navigator = document.CreateNavigator();
var dataNav = navigator.Select("/root/data");
foreach (XPathNavigator item in dataNav)
{
var name = item.GetAttribute("name", String.Empty);
#>
public const String <#= name#> = "<#= name#>";
<# } #>
}
}
}
...