大约有 40,000 项符合查询结果（耗时：0.0480秒） [XML]
What is “entropy and information gain”?
...are relevant to the target class we want to predict. Some example features include: first/last letter, length, number of vowels, does it end with a vowel, etc.. So after feature extraction, our data looks like:
# name ends-vowel num-vowels length gender
# -----------------------------------...
How to check if a database exists in SQL Server?
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@MadTigger: you shouldn't include [ ] in your call to db_id; that's SQL syntax, not part of the database name.
– Jacob Krall
Jul 7 '17 at 15:18
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Is there any way to not return something using CoffeeScript?
... Using "Try Coffeescript" at coffeescript.org, one can see that explicitly including "return" in coffeescript removes the return from the javascript; whereas, with "undefined", the javascript function ends with "return void 0;"
– Daniel
Mar 28 '14 at 16:39
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Is there a simple, elegant way to define singletons? [duplicate]
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Python being battery-included this should be part of a desing_pattern standard library, thanks
– dashesy
Aug 31 '14 at 0:23
2
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Can I assume (bool)true == (int)1 for any C++ compiler?
...constant expression except that: it shall not contain a cast; identifiers (including those lexically identical to keywords) are interpreted as described below;" Though not stated as direct permission, this clearly contemplates the possibility of a macro that's "lexically identical" to a keyword.
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How do I reload .bashrc without logging out and back in?
...ell (sourcing) makes, the current shell and its state are preserved, which includes environment variables, shell variables, shell options, shell functions, and command history.
exec bash, or, more robustly, exec "$BASH"[1],
will replace your current shell with a new instance, and therefore only pre...
Prevent nginx 504 Gateway timeout using PHP set_time_limit()
...NAME $document_root$fastcgi_script_name;
fastcgi_read_timeout 180;
include fastcgi_params;
}
Now just restart php-fpm and nginx and there should be no more timeouts for requests taking less than 180 seconds.
share...
Regexp Java for password validation
...t (8) characters in length where the system can support it.
Passwords must include characters from at least two (2) of these groupings: alpha, numeric, and special characters.
^.*(?=.{8,})(?=.*\d)(?=.*[a-zA-Z])|(?=.{8,})(?=.*\d)(?=.*[!@#$%^&])|(?=.{8,})(?=.*[a-zA-Z])(?=.*[!@#$%^&]).*$
I ...
Getting parts of a URL (Regex)
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A single regex to parse and breakup a
full URL including query parameters
and anchors e.g.
https://www.google.com/dir/1/2/search.html?arg=0-a&arg1=1-b&arg3-c#hash
^((http[s]?|ftp):\/)?\/?([^:\/\s]+)((\/\w+)*\/)([\w\-\.]+[^#?\s]+)(.*)?(#[\w\-]+)?$
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How to Get True Size of MySQL Database?
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None of the answers include the overhead size and the metadata sizes of tables.
Here is a more accurate estimation of the "disk space" allocated by a database.
SELECT ROUND((SUM(data_length+index_length+data_free) + (COUNT(*) * 300 * 1024))/10...