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What is the Simplest Way to Reverse an ArrayList?
...e other elements down the array, so the array stays a constant size essentially. Interesting solutions, thanks!
– Tony Chan
Nov 7 '14 at 3:01
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How can I check for Python version in a program that uses new language features?
...rom the question that needed addressing is that a program must be syntactically correct for that version of python to even begin executing, so using new syntax precludes a program from starting on older versions of the interpreter. eval works around that
– Autoplectic
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sql “LIKE” equivalent in django query
...s. I have made the lookup into a Django-like-lookup application. After installing it the __like lookup with the % and _ wildcards will be enabled.
All the necessary code in the application is:
from django.db.models import Lookup
from django.db.models.fields import Field
@Field.register_lookup
cl...
C++ performance vs. Java/C#
...p of a virtual machine which abstracts away the native architecture. Logically it would seem impossible for Java or C# to match the speed of C++ because of this intermediate step, however I've been told that the latest compilers ("hot spot") can attain this speed or even exceed it.
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How to append rows to an R data frame
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Not knowing what you are trying to do, I'll share one more suggestion: Preallocate vectors of the type you want for each column, insert values into those vectors, and then, at the end, create your data.frame.
Continuing with Julian's f3 (a preallocated data.frame) as the fastest option so far, def...
Python extending with - using super() Python 3 vs Python 2
Originally I wanted to ask this question , but then I found it was already thought of before...
5 Answers
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E11000 duplicate key error index in mongodb mongoose
... null value.
In other words, a sparse index is ok with multiple documents all having null values.
sparse indexes
From comments:
Your error says that the key is named mydb.users.$email_1 which makes me suspect that you have an index on both users.email and users.local.email (The former being old an...
What are “first class” objects?
...as
any other object.
A first class object is an entity that can be dynamically created, destroyed, passed to a function, returned as a value, and have all the rights as other variables in the programming language have.
Depending on the language, this can
imply:
being expressible as ...
Detecting when the 'back' button is pressed on a navbar
...to work under certain scenarios in iOS 8+. I can't verify that that is actually the case without further details.
For those of you however in that situation there's an alternative. Detecting when a view controller is being popped is possible by overriding willMove(toParentViewController:). The basi...
Ignore .pyc files in git repository
...t to to do it beforehand, if you just add the line to the .gitignore file, all previously committed .pyc files will still be tracked, so you'll need to remove them from the repository.
If you are on a Linux system (or "parents&sons" like a MacOSX), you can quickly do it with just this one line ...