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What does rake db:test:prepare actually do?

...orial videos and I can't figure out what the db:test:prepare command actually does. Can someone provide an explanation? ...
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Flask SQLAlchemy query, specify column names

... do I specify the column that I want in my query using a model (it selects all columns by default)? I know how to do this with the sqlalchmey session: session.query(self.col1) , but how do I do it with with models? I can't do SomeModel.query() . Is there a way? ...
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Iterating through directories with Python

... Another way of returning all files in subdirectories is to use the pathlib module, introduced in Python 3.4, which provides an object oriented approach to handling filesystem paths (Pathlib is also available on Python 2.7 via the pathlib2 module on P...
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ImportError in importing from sklearn: cannot import name check_build

... Worked for me after installing scipy. share | improve this answer | follow | ...
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How to calculate the bounding box for a given lat/lng location?

... I suggest to approximate locally the Earth surface as a sphere with radius given by the WGS84 ellipsoid at the given latitude. I suspect that the exact computation of latMin and latMax would require elliptic functions and would not yield an appreciable ...
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How to read the mode field of git-ls-tree's output

...ing 0 on the top lines (e.g. 0170000 instead of 170000), since it is 0 for all lines, why not just omit it? – Ciro Santilli 郝海东冠状病六四事件法轮功 Aug 22 '14 at 7:47 ...
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Storing custom objects in an NSMutableArray in NSUserDefaults

...ray]; if (oldSavedArray != nil) objectArray = [[NSMutableArray alloc] initWithArray:oldSavedArray]; else objectArray = [[NSMutableArray alloc] init]; } You should check that the data returned from the user defaults is not nil, because I believe unarchiving from nil causes a...
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Instance variable: self vs @

...ng self.age tells the object to send itself the message age, which will usually return the instance variable @age — but could do any number of other things depending on how the age method is implemented in a given subclass. For example, you might have a MiddleAgedSocialite class that always report...
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Updating and committing only a file's permissions using git version control

...n: git config core.filemode true Then, you should be able to commit normally your files. It will only commit the permission changes. share | improve this answer | follow ...
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What is the difference between '/' and '//' when used for division?

...floating point division, and the latter is floor division, sometimes also called integer division. In Python 2.2 or later in the 2.x line, there is no difference for integers unless you perform a from __future__ import division, which causes Python 2.x to adopt the 3.x behavior. Regardless of the ...