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Access nested dictionary items via a list of keys?

...ataDict, mapList): return reduce(operator.getitem, mapList, dataDict) and reuse getFromDict to find the location to store the value for setInDict(): def setInDict(dataDict, mapList, value): getFromDict(dataDict, mapList[:-1])[mapList[-1]] = value All but the last element in mapList is need...
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Convert columns to string in Pandas

...e looking for the to_json function, which will convert keys to valid json (and therefore your keys to strings): In [11]: df = pd.DataFrame([['A', 2], ['A', 4], ['B', 6]]) In [12]: df.to_json() Out[12]: '{"0":{"0":"A","1":"A","2":"B"},"1":{"0":2,"1":4,"2":6}}' In [13]: df[0].to_json() Out[13]: '{"...
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How to resize an image with OpenCV2.0 and Python2.6

I want to use OpenCV2.0 and Python2.6 to show resized images. I used and adopted this example but unfortunately, this code is for OpenCV2.1 and does not seem to be working on 2.0. Here my code: ...
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How can I find the length of a number?

...34567; x.toString().length; This process will also work forFloat Number and for Exponential number also. share | improve this answer | follow | ...
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PHP: How to send HTTP response code?

... I just found this question and thought it needs a more comprehensive answer: As of PHP 5.4 there are three methods to accomplish this: Assembling the response code on your own (PHP >= 4.0) The header() function has a special use-case that detects...
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How do Trigonometric functions work?

So in high school math, and probably college, we are taught how to use trig functions, what they do, and what kinds of problems they solve. But they have always been presented to me as a black box. If you need the Sine or Cosine of something, you hit the sin or cos button on your calculator and you'...
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Nesting await in Parallel.ForEach

...The whole idea behind Parallel.ForEach() is that you have a set of threads and each thread processes part of the collection. As you noticed, this doesn't work with async-await, where you want to release the thread for the duration of the async call. You could “fix” that by blocking the ForE...
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Open file dialog and select a file using WPF controls and C#

I have a TextBox named textbox1 and a Button named button1 . When I click on button1 I want to browse my files to search only for image files (type jpg, png, bmp...). And when I select an image file and click Ok in the file dialog I want the file directory to be written in the textbox1.tex...
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Can not connect to local PostgreSQL

...really looks like a file permissions error. Unix domain sockets are files and have user permissions just like any other. It looks as though the OSX user attempting to access the database does not have file permissions to access the socket file. To confirm this I've done some tests on Ubuntu and p...
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What is the difference between “INNER JOIN” and “OUTER JOIN”?

Also how do LEFT JOIN , RIGHT JOIN and FULL JOIN fit in? 27 Answers 27 ...