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How to change the order of DataFrame columns?
...mean(1))
http://pandas.pydata.org/pandas-docs/stable/dsintro.html#column-selection-addition-deletion
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Objective-C and Swift URL encoding
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To escape the characters you want is a little more work.
Example code
iOS7 and above:
NSString *unescaped = @"http://www";
NSString *escapedString = [unescaped stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLHo...
Why is it slower to iterate over a small string than a small list?
...string took longer than doing the same operation on a list of small single character strings. Any explanation? It's almost 1.35 times as much time.
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Debugging with command-line parameters in Visual Studio
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Make sure you have the correct Configuration selected in the dropdown at the top of the Property pages, i.e. the same configuration as the one you are trying to run.
– Steve Smith
Jan 4 '18 at 14:51
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Input from the keyboard in command line application
...wlines in the string with this. Strip them out with string.stringByTrimmingCharactersInSet(NSCharacterSet.newlineCharacterSet())
– pk-nb
Jul 6 '14 at 16:27
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Convert data.frame column format from character to factor
...yr::mutate_if() to convert all character columns or dplyr::mutate_at() for select named character columns to factors:
library(dplyr)
# all character columns to factor:
df <- mutate_if(df, is.character, as.factor)
# select character columns 'char1', 'char2', etc. to factor:
df <- mutate_at(d...
How to display a dynamically allocated array in the Visual Studio debugger?
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For beginners: If you select "a" variable, right click and add to watch list (inspect), if you open de debugger view in the list of watched values (I can't find the name of the window right now), you can double click "a" and rename it "a,X" where ...
Type definition in object literal in TypeScript
...ally need a type that you can be lazily initialized: Mark it is a nullable union type (null or Type). The type system will prevent you from using it without first ensuring it has a value.
In tsconfig.json, make sure you enable strict null checks:
"strictNullChecks": true
Then use this pattern an...
sql primary key and index
...dex
ON MyTable(ID)
INCLUDE (Name, Address)
So, when you use this query:
SELECT ID, Name, Address FROM MyTable WHERE ID > 1000
SQL Server will give you the result only using the index you've created and it'll not read anything from the actual table.
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Callback functions in C++
... for jumping, the engine can call
game_core_instance.update_keybind(newly_selected_key, &player_jump);
and thus change the behaviour of a call to key_pressed (which the calls player_jump) once this button is pressed the next time ingame.
What are callables in C++(11)?
See C++ concepts: Call...