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Python None comparison: should I use “is” or ==?
...hat == will do depends on the exact type of the operands and even on their ordering.
This recommendation is supported by PEP 8, which explicitly states that "comparisons to singletons like None should always be done with is or is not, never the equality operators."
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Regular expression for a hexadecimal number?
...
If you're using Perl or PHP, you can replace
[0-9a-fA-F]
with:
[[:xdigit:]]
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How many files can I put in a directory?
... We have hundreds of thousands of images in our social network website. In order to improve the performance we were forced to have 100 (or 1000 for some files) sub directories and distribute the files into them (ext3 on linux+ Apache for us).
– wmac
Jul 24 '14 ...
Unique Key constraints for multiple columns in Entity Framework
...et; }
The second parameter in the attribute is where you can specify the order of the columns in the index.
More information: MSDN
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Populate a Razor Section From a Partial
...Builder sb = new StringBuilder();
foreach (var item in requiredScripts.OrderByDescending(i => i.Priority))
{
sb.AppendFormat("<script src=\"{0}\" type=\"text/javascript\"></script>\n", item.Path);
}
return new HtmlString(sb.ToString());
}
public class ResourceI...
Is Big O(logn) log base e?
... big-O notation is usually written showing only the asymptotically highest order of n, so constant coefficients will drop away. Since a different logarithm base is equivalent to a constant coefficient, it is superfluous.
That said, I would probably assume log base 2.
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Does Python have a string 'contains' substring method?
...contains__(self, item), __iter__(self), and __getitem__(self, key) in that order to determine whether an item lies in a given contains. Implement at least one of those methods to make in available to your custom type.
– BallpointBen
Aug 17 '18 at 7:02
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namedtuple and default values for optional keyword arguments
...(Node._fields)
>>> Node()
Node(val=None, left=None, right=None)
Order
In all versions of Python, if you set fewer default values than exist in the namedtuple, the defaults are applied to the rightmost parameters. This allows you to keep some arguments as required arguments.
>>>...
Selecting a row of pandas series/dataframe by integer index
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@kilojoules .iloc looks things up by their order in the index (e.g. .iloc[[2]]) is the second "row" in df. That row happens to be at index location 4. .loc looks them up by their index value. So maybe "iloc" is like "i" as in A[i]? :)
– Jim K...
Sass or Compass without ruby?
...f (sass & compass) IS written in Ruby. So you'll definitely need it in order to run it.
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