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How do I specify local .gem files in my Gemfile?
...talling .gem packages, but you can specify all kinds of locations on a gem-by-gem basis by editing your Gemfile.
Specifying a :path attribute will install the gem from that path on your local machine.
gem "foreman", path: "/Users/pje/my_foreman_fork"
Alternately, specifying a :git attribute will...
How do I use floating-point division in bash?
...IDTH/$IMG2_WIDTH") without $(( )) (double parentheses) ; which is expanded by the bash before executing command
– Nahuel Fouilleul
Oct 4 '12 at 7:32
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Sample random rows in dataframe
...red Nov 25 '11 at 19:15
John ColbyJohn Colby
20.3k33 gold badges5151 silver badges6767 bronze badges
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Why is there a difference in checking null against a value in VB.NET and C#?
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VB.NET and C#.NET are different languages, built by different teams who have made different assumptions about usage; in this case the semantics of a NULL comparison.
My personal preference is for the VB.NET semantics, which in essence gives NULL the semantics "I don't know...
grepping using the “|” alternative operator
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By default, grep treats the typical special characters as normal characters unless they are escaped. So you could use the following:
grep 'gene\|exon' AT5G60410.gff
However, you can change its mode by using the following f...
Can't subtract offset-naive and offset-aware datetimes
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UTC doesn't need a timezone, by definition. If the other datetime object is timezone aware then surely that provides the offset relative to UTC. UTC times may not have a timezone but they are not 'naive' and Python is handling this wrongly.
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INSERT … ON DUPLICATE KEY (do nothing)
...:
simple.
cons:
too slow.
auto-increment key will CHANGE(increase by 1) if there is entry matches unique key or primary key, because it deletes the old entry then insert new one.
2. INSERT IGNORE
pros:
simple.
cons:
auto-increment key will not change if there is entry matches uni...
Best way to test exceptions with Assert to ensure they will be thrown
...is not sufficient. The exception may not be catchable - since it's thrown by a method that is invoked by reflection - or perhaps I just want to check that other conditions hold, say a transaction is rolled back or some value has still been set. In these cases I wrap it in a try/catch block that ex...
jQuery how to bind onclick event to dynamically added HTML element [duplicate]
... Indeed, when you are targeting known markup structures created by some other code. But here he was inserting the elements himself, and there is no clear selector for them (it's just an anchor, which there might be many of), so he would have to add additional markup to be able to target t...
How to use single storyboard uiviewcontroller for multiple subclass
...ryboard are linked up to their properties in the view controller.
It will by default initialize with the view controller that is specified in the storyboard definition.
If you are trying to gain reuse of UI elements you created in the storyboard, they still must be linked or associated to properti...