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What is the best way to implement nested dictionaries?
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183
What is the best way to implement nested dictionaries in Python?
This is a bad idea, don't do ...
ZSH iterm2 increase number of lines history
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3 Answers
3
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How to convert a boolean array to an int array
...gt;> x
array([ True, False, True], dtype=bool)
>>> x + [1, 2, 3]
array([2, 2, 4])
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How to check the version of GitLab?
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336
I have updated my server to GitLab 6.6.4 and finally found the way to get version of GitLab re...
What exactly is Arel in Rails 3.0?
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What exactly is Arel in Rails 3.0?
It's an object model for an algebra of relational query operators.
I understand that it is a replacement for ActiveRecord
No, it isn't. It's a replacement for hand-crafting SQL queries in strings. It is a common query...
Making an array of integers in iOS
...] = i;
// to get one of them
NSLog (@"The 4th integer is: %d", myIntegers[3]);
Or, you can use an NSArray or NSMutableArray, but here you will need to wrap up each integer inside an NSNumber instance (because NSArray objects are designed to hold class instances).
NSMutableArray *myIntegers = [NS...
Changing git commit message after push (given that no one pulled from remote)
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edited May 23 '17 at 10:31
Community♦
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answered Jan 24 '12 at 2:02
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How do you manually execute SQL commands in Ruby On Rails using NuoDB
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edited Jan 23 '19 at 10:24
Jan Klimo
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Update MongoDB field using value of another field
..."name": { "$concat": ["$firstName", " ", "$lastName"]}}}
]
)
MongoDB 3.4+
In 3.4+ you can use $addFields and the $out aggregation pipeline operators.
db.collection.aggregate(
[
{ "$addFields": {
"name": { "$concat": [ "$firstName", " ", "$lastName" ] }
}},
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Fastest way to replace NAs in a large data.table
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system.time(a_gdata = f_gdata(dt1))
user system elapsed
18.805 12.301 134.985
system.time(a_andrie = f_andrie(dt1))
Error: cannot allocate vector of size 305.2 Mb
Timing stopped at: 14.541 7.764 68.285
system.time(f_dowle(dt1))
user system elapsed
7.452 4.144 19.590 # EDIT h...