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Modifying a subset of rows in a pandas dataframe
...The df.A==0 expression creates a boolean series that indexes the rows, 'B' selects the column. You can also use this to transform a subset of a column, e.g.:
df.loc[df.A==0, 'B'] = df.loc[df.A==0, 'B'] / 2
I don't know enough about pandas internals to know exactly why that works, but the basic is...
How can I do an UPDATE statement with JOIN in SQL Server?
...oesn't support MERGE):
ANSI/ISO:
update ud
set assid = (
select sale.assid
from sale
where sale.udid = ud.id
)
where exists (
select *
from sale
where sale.udid = ud.id
);
MySQL:
update ud u
inner join sale s on
u.id = s.udid
...
What does git rev-parse do?
... in plumbing commands as short for "revision" and generally meaning the 40-character SHA1 hash for a commit. The command rev-list for example prints a list of 40-char commit hashes for a branch or whatever.
In this case the name might be expanded to parse-a-commitish-to-a-full-SHA1-hash. While the ...
How can I use swift in Terminal?
...
sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer
then you can do one of these:
xcrun swift
lldb --repl
As of Xcode 6.1 - typing swift in the terminal launches the REPL as well.
...
In Angular, I need to search objects in an array
...ById')($scope.fish, fish_id);
console.log(found);
$scope.selected = JSON.stringify(found);
}
}]);
If there are any questions just let me know.
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...
Reading Excel files from C#
...ed Properties=Excel 8.0;", fileName);
var adapter = new OleDbDataAdapter("SELECT * FROM [workSheetNameHere$]", connectionString);
var ds = new DataSet();
adapter.Fill(ds, "anyNameHere");
DataTable data = ds.Tables["anyNameHere"];
This is what I usually use. It is a little different because I u...
How do I rename a column in a SQLite database table?
...lite.org/images/syntax/alter-table-stmt.gif
Example:
CREATE TABLE tab AS SELECT 1 AS c;
SELECT * FROM tab;
ALTER TABLE tab RENAME COLUMN c to c_new;
SELECT * FROM tab;
db-fiddle.com demo
Android Support
As of writing, Android's API 27 is using SQLite package version 3.19.
Based on the cu...
LINQ - Left Join, Group By, and Count
...into j1
from j2 in j1.DefaultIfEmpty()
group j2 by p.ParentId into grouped
select new { ParentId = grouped.Key, Count = grouped.Count(t=>t.ChildId != null) }
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TFS: Updating branch with changes from main
...
From Visual Studio, open Source Control Explorer:
View | Team Explorer
Select your Team Project from Team Explorer, expand it, and double click Source Control
In the left-hand pane of Source Control Explorer, select your Team Project.
In the right-hand pane, find your mainline branch, right-clic...
How can I selectively escape percent (%) in Python strings?
...
>>> test = "have it break."
>>> selectiveEscape = "Print percent %% in sentence and not %s" % test
>>> print selectiveEscape
Print percent % in sentence and not have it break.
...