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What's the fastest way to merge/join data.frames in R?
...(y) from main.d group by g1, g2"))
)
The outputs from the two benchmark call comparing the merge calculations are:
Joining by: x
test replications elapsed relative user.self sys.self user.child sys.child
3 data.table 1 0.34 1.000000 0.31 0.01 NA NA
2 ...
Linux - Replacing spaces in the file names
...umber of files in a folder, and I want to replace every space character in all file names with underscores. How can I achieve this?
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UIViewContentModeScaleAspectFill not clipping
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If you want to expand your knowledge there is a really good article on how the iOS UIView stack is rendered. There is also a more in-depth article about the whole drawing pipeline.
In summary:
Rasterisation - All the view's content is rasterised (drawn or a offscreen pix...
Expression Versus Statement
...as one unit of execution, a thing that you did. The only reason it wasn't called a "line" was because sometimes it spanned multiple lines. An expression on its own couldn't do anything... you had to assign it to a variable.
1 + 2 / X
is an error in FORTRAN, because it doesn't do anything. You had...
Does Python have a ternary conditional operator?
...s ignored, or else when b is evaluated and returned but a is ignored.
This allows short-circuiting because when condition is true only a is evaluated and b is not evaluated at all, but when condition is false only b is evaluated and a is not evaluated at all.
For example:
>>> 'true' if True...
How to create a new object instance from a Type
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Glad to have finally found this, but second call is not exactly right, missing a quote and parms reversed, should be: ObjectType instance = (ObjectType)Activator.CreateInstance("MyAssembly","MyNamespace.ObjectType");
– ...
Django database query: How to get object by id?
Django automatically creates an id field as primary key.
6 Answers
6
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Getting indices of True values in a boolean list
...ode where I'm supposed to create a switchboard. I want to return a list of all the switches that are on. Here "on" will equal True and "off" equal False . So now I just want to return a list of all the True values and their position. This is all I have but it only return the position of the fir...
Efficiently updating database using SQLAlchemy ORM
...ngs in mind when using the ORM and plain SQL in the same transaction. Basically, from one side, ORM data modifications will only hit the database when you flush the changes from your session. From the other side, SQL data manipulation statements don't affect the objects that are in your session.
So...
How to add Google Analytics Tracking ID to GitHub Pages
... I have added them, however Google analytics say the Tracking is not installed. My page as specified in G-Analytics is http://avi-aryan.github.io
– Avi
Jul 15 '13 at 12:33
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