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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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Where do you store your salt strings?
...ght about a salt per user I was thinking that a single salt would work for all users. What about a salt that is stored as an XML file that is loaded by the App Server? or maybe somehow hardcoded into a servlet?
– jigzat
Jul 25 '12 at 2:58
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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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Read String line by line
...s = myString.split(System.getProperty("line.separator"));
This gives you all lines in a handy array.
I don't know about the performance of split. It uses regular expressions.
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What is an SDL renderer?
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SDL_Window
SDL_Window is the struct that holds all info about the Window itself: size, position, full screen, borders etc.
SDL_Renderer
SDL_Renderer is a struct that handles all rendering. It is tied to a SDL_Window so it can only render within that SDL_Window. It als...
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...
Flexbox Not Centering Vertically in IE
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I found that ie browser have problem to vertically align inner containers, when only the min-height style is set or when height style is missing at all. What I did was to add height style with some value and that fix the issue for me.
for example :
.outer
{
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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...