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How does deriving work in Haskell?
Algebraic Data Types (ADTs) in Haskell can automatically become instances of some typeclasse s (like Show , Eq ) by deriving from them.
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Renaming columns in pandas
...UMNS
Use the df.rename() function and refer the columns to be renamed. Not all the columns have to be renamed:
df = df.rename(columns={'oldName1': 'newName1', 'oldName2': 'newName2'})
# Or rename the existing DataFrame (rather than creating a copy)
df.rename(columns={'oldName1': 'newName1', 'oldNam...
'innerText' works in IE, but not in Firefox
...current beta release, and has been in aurora for a while. What this practically means is you can start developing sites using innerText only and expect it to work (with possible quirks) on all current browsers in the near future, and old-IE too.
– Bob
Feb 22 '1...
How to replace local branch with remote branch entirely in Git?
...contents of master. So if you're on e.g. a feature-branch, it will replace all its commits with master, so make sure you've checked out the branch you're replacing first.
– Zoltán
Jul 15 '16 at 8:29
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Flask-SQLalchemy update a row's information
...e many objects to be updated.
If you want to give add_user permission to all the admins,
rows_changed = User.query.filter_by(role='admin').update(dict(permission='add_user'))
db.session.commit()
Notice that filter_by takes keyword arguments (use only one =) as opposed to filter which takes an e...
When should you not use virtual destructors?
...o not declare a virtual destructor for a class? When should you specifically avoid writing one?
12 Answers
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How do I get the name of the active user via the command line in OS X?
...if you are ssh'ed into a machine and want to see if a user is logged on locally. If they are not, the command will return "root".
– Tim Dearborn
Jan 15 '16 at 1:17
add a comme...
python generator “send” function purpose?
...t's useful, one of the best use cases I've seen is Twisted's @defer.inlineCallbacks. Essentially it allows you to write a function like this:
@defer.inlineCallbacks
def doStuff():
result = yield takesTwoSeconds()
nextResult = yield takesTenSeconds(result * 10)
defer.returnValue(nextResu...
What does the git index contain EXACTLY?
...ns an article on what an index includes:
The index is a binary file (generally kept in .git/index) containing a sorted list of path names, each with permissions and the SHA1 of a blob object; git ls-files can show you the contents of the index:
$ git ls-files --stage
100644 63c918c667fa005ff12ad89...
How to list all the files in a commit?
...ooking for a simple git command that provides a nicely formatted list of all files that were part of the commit given by a hash (SHA1), with no extraneous information.
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