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List comprehension vs map
... map when using exactly the same function:
$ python -mtimeit -s'xs=range(10)' 'map(hex, xs)'
100000 loops, best of 3: 4.86 usec per loop
$ python -mtimeit -s'xs=range(10)' '[hex(x) for x in xs]'
100000 loops, best of 3: 5.58 usec per loop
An example of how performance comparison gets completely r...
Checking for NULL pointer in C/C++ [closed]
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206
In my experience, tests of the form if (ptr) or if (!ptr) are preferred. They do not depend on ...
Compare integer in bash, unary operator expected
... specifying a default value for $i if $i is blank, as follows:
if [ "${i:-0}" -ge 2 ] ; then ...
This will substitute the value 0 instead of $i is $i is undefined. I still maintain the quotes because, again, if $i is a bunch of blanks then it does not count as undefined, it will not be replaced ...
Symbol for any number of any characters in regex?
...ace or any non-whitespace) as many times as possible down to and including 0.
[\s\S]*
This expression will match as few as possible, but as many as necessary for the rest of the expression.
[\s\S]*?
For example, in this regex [\s\S]*?B will match aB in aBaaaaB. But in this regex [\s\S]*B will...
CSS: transition opacity on mouse-out?
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202
You're applying transitions only to the :hover pseudo-class, and not to the element itself.
.i...
Entity Framework - Start Over - Undo/Rollback All Migrations
... to rollback all migrations you can use:
Update-Database -TargetMigration:0
or equivalent:
Update-Database -TargetMigration:$InitialDatabase
In some cases you can also delete database and all migration classes.
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Check if a number has a decimal place/is a whole number
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20 Answers
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Check variable equality against a list of values
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How to get a number of random elements from an array?
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edited Feb 20 '18 at 17:21
answered Oct 9 '13 at 10:52
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DbArithmeticExpression arguments must have a numeric common type
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edited Dec 14 '17 at 11:03
community wiki
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