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How do 20 questions AI algorithms work?

... I recommend reading about the game here: http://en.wikipedia.org/wiki/Twenty_Questions In particular the Computers section: The game suggests that the information (as measured by Shannon's entropy statistic) required to identif...
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pandas DataFrame: replace nan values with average of columns

... # To read data from csv file Dataset = pd.read_csv('Data.csv') X = Dataset.iloc[:, :-1].values # To calculate mean use imputer class from sklearn.impute import SimpleImputer imputer = SimpleImputer(missing_values=np.nan, strateg...
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What are the main performance differences between varchar and nvarchar SQL Server data types?

...ce is not the issue... but memory and performance will be. Double the page reads, double index size, strange LIKE and = constant behaviour etc Do you need to store Chinese etc script? Yes or no... And from MS BOL "Storage and Performance Effects of Unicode" Edit: Recent SO question highlighting...
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Can you have multiple $(document).ready(function(){ … }); sections?

... neatest thing to do. Try not to overuse them, as it will seriously affect readability. Other than that , it's perfectly legal. See the below: http://www.learningjquery.com/2006/09/multiple-document-ready Try this out: $(document).ready(function() { alert('Hello Tom!'); }); $(document).ready...
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Check whether a path is valid in Python without creating a file at the path's target

...rom this pathname is valid or # not, ignoring non-existent and non-readable path components. for pathname_part in pathname.split(os.path.sep): try: os.lstat(root_dirname + pathname_part) # If an OS-specific exception is raised, its error code ...
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How to find keys of a hash?

... # OUTPUT # > a 1 # > b 2 # > ["a", "b"] However, since ECMA5 already added Object.keys you might as well use: Object.defineProperty(Object.prototype, 'keys', { value: function keys() { return Object.keys(this); }, enumerable: false }); Original answer Object.prototype.keys ...
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Is a DIV inside a TD a bad idea?

It seems like I heard/read somewhere that a <div> inside of a <td> was a no-no. Not that it won't work, just something about them not being really compatible based on their display type. Can't find any evidence to back up my hunch, so I may be totally wrong. ...
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Iterate keys in a C++ map

...form_iterator. [Tip: when looking at Boost documentation for a new class, read the "examples" at the end first. You then have a sporting chance of figuring out what on earth the rest of it is talking about :-)] share ...
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Show compose SMS view in Android

... @djk thanks i want to Read all contacts and want own page for sending sms with auto complete but i am not able to read contacts any good tutorial ? – Guru Oct 1 '12 at 12:59 ...
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MySQL > Table doesn't exist. But it does (or it should)

... After the first machine restart/MySQL startup, I got the error. Then, I read this answer. I stopped/started MySQL through System Preferences and it was fixed. – Jeff Evans Jun 11 '14 at 15:19 ...