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Python argparse: Make at least one argument required

... args = vars(parser.parse_args()) if not any(args.values()): parser.error('No arguments provided.') share | improve this answer | ...
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HTML5 Pre-resize images before uploading

...le); var ctx = canvas.getContext("2d"); ctx.drawImage(img, 0, 0); var MAX_WIDTH = 800; var MAX_HEIGHT = 600; var width = img.width; var height = img.height; if (width > height) { if (width > MAX_WIDTH) { height *= MAX_WIDTH / width; width = MAX_WIDTH; } } else { if (height &gt...
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Relative frequencies / proportions with dplyr

... Try this: mtcars %>% group_by(am, gear) %>% summarise(n = n()) %>% mutate(freq = n / sum(n)) # am gear n freq # 1 0 3 15 0.7894737 # 2 0 4 4 0.2105263 # 3 1 4 8 0.6153846 # 4 1 5 5 0.3846154 From the dplyr vigne...
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Best way to parse RSS/Atom feeds with PHP [closed]

...e RSS experience and needs a better parser. – duality_ Jul 30 '11 at 13:49 3 In case somebody nee...
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PHP code to convert a MySQL query to CSV [closed]

... SELECT * INTO OUTFILE "c:/mydata.csv" FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' LINES TERMINATED BY "\n" FROM my_table; (the documentation for this is here: http://dev.mysql.com/doc/refman/5.0/en/select.html) or: $select = "SELECT * FROM table_name"; $export = mysql_query ( $sel...
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Align image in center and middle within div

...00%; height:100%"> <img src="http://www.garcard.com/images/garcard_symbol.png"> </div> JSFiddle share | improve this answer | follow ...
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Octave-Gnuplot-AquaTerm error: set terminal aqua enhanced title “Figure 1”…unknown terminal type"

I've installed Octave and gnuplot via Homebrew, and downloaded AquaTerm.dmg. When I try to plot, I get the following message: ...
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Basic HTTP authentication with Node and Express 4

...he bare minimum you need: (you don't even need to parse the credentials at all) function (req, res) { //btoa('yourlogin:yourpassword') -> "eW91cmxvZ2luOnlvdXJwYXNzd29yZA==" //btoa('otherlogin:otherpassword') -> "b3RoZXJsb2dpbjpvdGhlcnBhc3N3b3Jk" // Verify credentials if ( req.headers.a...
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find filenames NOT ending in specific extensions on Unix?

Is there a simple way to recursively find all files in a directory hierarchy, that do not end in a list of extensions? E.g. all files that are not *.dll or *.exe ...
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Python __call__ special method practical example

I know that __call__ method in a class is triggered when the instance of a class is called. However, I have no idea when I can use this special method, because one can simply create a new method and perform the same operation done in __call__ method and instead of calling the instance, you can c...