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Why are Python lambdas useful? [closed]

...ut lambda functions? Like lambda x: x**2 + 2*x - 5 Those things are actually quite useful. Python supports a style of programming called functional programming where you can pass functions to other functions to do stuff. Example: mult3 = filter(lambda x: x % 3 == 0, [1, 2, 3, 4, 5, 6, 7, 8, 9])...
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python dataframe pandas drop column using int

... columns with identical names, the solutions given here so far will remove all of the columns, which may not be what one is looking for. This may be the case if one is trying to remove duplicate columns except one instance. The example below clarifies this situation: # make a df with duplicate col...
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image processing to improve tesseract OCR accuracy

... highly pixellated - for example that generated by fax machines - is especially difficult for tesseract to process - presumably all those jagged edges to the characters confound the shape-recognition algorithms. ...
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ARC and bridged cast

...__bridge_transfer? Otherwise it would seem that the moment CFRelease() is called the object is gone and points to nothing. Similarly, when you use __bridge_retain, does ARC reduce the op's retain count by 1? Else it seems that the object would never be properly released. – Tony...
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Where are $_SESSION variables stored?

...ariable storage is determined by PHP's session.save_path configuration. Usually this is /tmp on a Linux/Unix system. Use the phpinfo() function to view your particular settings if not 100% sure by creating a file with this content in the DocumentRoot of your domain: <?php phpinfo(); ?> ...
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What is the difference between tinyint, smallint, mediumint, bigint and int in MySQL?

What is the difference between tinyint, smallint, mediumint, bigint and int in MySQL? 6 Answers ...
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What are the differences between concepts and template constraints?

...To quickly summarise their meanings: Constraint - A predicate over statically evaluable properties of a type. Purely syntactic requirements. Not a domain abstraction. Axioms - Semantic requirements of types that are assumed to be true. Not statically checked. Concepts - General, abstract requireme...
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File Explorer in Android Studio

... files should be in: DDMS-> File Explorer ->data -> data -> MY_PACKAGE_NAME -> shared_prefs -> YOUR_PREFERENCE_NAME.xml share | improve this answer | fol...
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Google Maps: how to get country, state/province/region, city given a lat/long value?

... What you are looking for is called reverse geocoding. Google provides a server-side reverse geocoding service through the Google Geocoding API, which you should be able to use for your project. This is how a response to the following request would look ...
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Splitting templated C++ classes into .hpp/.cpp files--is it possible?

...the implementation of a template class in a separate cpp file and compile. All the ways to do so, if anyone claims, are workarounds to mimic the usage of separate cpp file but practically if you intend to write a template class library and distribute it with header and lib files to hide the implemen...