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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...
MySQL indexes - what are the best practices?
...t them. Generally I put an index on any fields that I will be searching or selecting using a WHERE clause but sometimes it doesn't seem so black and white.
...
How to change package name of an Android Application
...
Right-click on the package name (src/com.android.gesture.builder).
Select Refactor > Rename and change the name, for example to
com.android.gestureNEW.builder.
Open the manifest file. Inside the
<manifest> tag, change the package name to
com.android.gestureNEW.builder.
...
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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How to select different app.config for several build configurations
...ctory. So if you had PatternPA.Test.Integration project and a Debug config selected, in the output folder after the build you will find a PatternPA.Test.Integration.dll.config file which was copied from Config\App.Debug.config and renamed afterwards.
These are some notes you can leave in the config...
How to get Time from DateTime format in SQL?
...
SQL Server 2008:
SELECT cast(AttDate as time) [time]
FROM yourtable
Earlier versions:
SELECT convert(char(5), AttDate, 108) [time]
FROM yourtable
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What is the use of GO in SQL Server Management Studio & Transact SQL?
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gbn make it SELECT and look at what happens :-)
– SQLMenace
Feb 19 '10 at 21:09
14
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How to put a UserControl into Visual Studio toolBox
...ialog with registered components pops up. in this dialog click "Browse" to select your assembly with the usercontrol you want to use.
PS.
This assembly should be registered before.
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TFS: Updating branch with changes from main
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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...
PostgreSQL: Modify OWNER on all tables simultaneously in PostgreSQL
...and sequences too. Here's what I did:
Tables:
for tbl in `psql -qAt -c "select tablename from pg_tables where schemaname = 'public';" YOUR_DB` ; do psql -c "alter table \"$tbl\" owner to NEW_OWNER" YOUR_DB ; done
Sequences:
for tbl in `psql -qAt -c "select sequence_name from information_schem...