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Null coalescing in powershell
...t the Powershell versions involving functions/aliases will always evaluate all arguments. If this is a problem, use the if expression form.
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Regex - Should hyphens be escaped? [duplicate]
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Correct on all fronts. Outside of a character class (that's what the "square brackets" are called) the hyphen has no special meaning, and within a character class, you can place a hyphen as the first or last character in the range (e.g....
Initializing a static std::map in C++
... Every time I see something like that done with C++, I think of all the horrendous template code that must be behind it. Good example!
– Greg Hewgill
Sep 26 '08 at 10:22
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Python decorators in classes
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Would something like this do what you need?
class Test(object):
def _decorator(foo):
def magic( self ) :
print "start magic"
foo( self )
print "end magic"
return magic
@_decorator
def bar( self ) :
print "normal call"
test ...
Hidden features of Perl?
What are some really useful but esoteric language features in Perl that you've actually been able to employ to do useful work?
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Is there an equivalent to CTRL+C in IPython Notebook in Firefox to break cells that are running?
...errupt the entire iPython Notebook server. This will stop iPython Notebook alltogether, which means it won't be possible to restart or save your work, so this is obviously not a great solution (you need to hit CTRL+C twice because it's a safety feature so that people don't do it by accident). In cas...
SQL UPDATE SET one column to be equal to a value in a related table referenced by a different column
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Without the update-and-join notation (not all DBMS support that), use:
UPDATE QuestionTrackings
SET QuestionID = (SELECT QuestionID
FROM AnswerTrackings
WHERE AnswerTrackings.AnswerID = QuestionTrackings.AnswerID)
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Advantages to Using Private Static Methods
When creating a class that has internal private methods, usually to reduce code duplication, that don't require the use of any instance fields, are there performance or memory advantages to declaring the method as static?
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How to refer to relative paths of resources when working with a code repository
...Try to use a filename relative to the current files path. Example for './my_file':
fn = os.path.join(os.path.dirname(__file__), 'my_file')
In Python 3.4+ you can also use pathlib:
fn = pathlib.Path(__file__).parent / 'my_file'
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Find the most common element in a list
...roups by the item only (via operator.itemgetter). The auxiliary function, called once per grouping during the max computation, receives and internally unpacks a group - a tuple with two items (item, iterable) where the iterable's items are also two-item tuples, (item, original index) [[the items of ...