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What exactly do “u” and “r” string flags do, and what are raw string literals?
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There's not really any "raw string"; there are raw string literals, which are exactly the string literals marked by an 'r' before the opening quote.
A "raw string literal" is a slightly different syntax for a string literal, in which a ba...
Profiling Django
...at queries are executed on each page and how much time they take. It's a really useful, powerful and easy to use tool.
Also, read recommendations about Django performance in Database access optimization from the documentation.
And Django performance tips by
Jacob Kaplan-Moss.
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Should Javadoc comments be added to the implementation?
...methods that are implementation only (not overrides), sure, why not, especially if they are public.
If you have an overriding situation and you are going to replicate any text, then definitely not. Replication is a surefire way of causing discrepancies. As a result, users would have a different und...
Clang optimization levels
...ass=Arguments
As pointed out in Geoff Nixon's answer (+1), clang additionally runs some higher level optimizations, which we can retrieve with:
echo 'int;' | clang -xc -O3 - -o /dev/null -\#\#\#
Documentation of individual passes is available here.
With version 6.0 the passes are as follow...
Drop unused factor levels in a subsetted data frame
...tion, a new data frame is created. However, the factor variable retains all of its original levels, even when/if they do not exist in the new dataframe.
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How to set timeout on python's socket recv method?
...lect() to wait until data is available or until the timeout occurs. Only call recv() when data is actually available. To be safe, we also set the socket to non-blocking mode to guarantee that recv() will never block indefinitely. select() can also be used to wait on more than one socket at a time...
Xcode Command /usr/bin/codesign failed with exit code 1 : errSecInternalComponent
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Open Keychain Access, then in the File menu select Lock All Keychains.
Then go back to Xcode and clean and rebuild. It will prompt you for your password again to unlock the keychain.
After this, assuming you have no other compile issues, it will succeed!
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How to convert lazy sequence to non-lazy in Clojure
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doall is all you need. Just because the seq has type LazySeq doesn't mean it has pending evaluation. Lazy seqs cache their results, so all you need to do is walk the lazy seq once (as doall does) in order to force it all, and t...
How to run Visual Studio post-build events for debug build only
...figuration)" == "Debug" worked for me. BTW, if you want to do something in all other configs, use if NOT "$(Configuration)" == "Debug".
– Ralf Hundewadt
Jun 29 '17 at 9:46
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A definitive guide to API-breaking changes in .NET
... information as possible regarding API versioning in .NET/CLR, and specifically how API changes do or do not break client applications. First, let's define some terms:
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