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How to send emails from my Android application?
...hers can see this. I missed this portion and had to deal with this problem for a while!
– ChallengeAccepted
Aug 6 '14 at 9:50
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How to detect if a specific file exists in Vimscript?
I'm looking for an elegant way in Vimscript to check if a file exists in the current directory.
4 Answers
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Regex how to match an optional character
...write [A-Z]{0,1} which would mean the same, but that's what the ? is there for.)
You could improve your regex to
^([0-9]{5})+\s+([A-Z]?)\s+([A-Z])([0-9]{3})([0-9]{3})([A-Z]{3})([A-Z]{3})\s+([A-Z])[0-9]{3}([0-9]{4})([0-9]{2})([0-9]{2})
And, since in most regex dialects, \d is the same as [0-9]:
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How to create abstract properties in python abstract classes
...d to an abstract method.
Note: Order matters, you have to use @property before @abstractmethod
Python 3.3+: (python docs):
class C(ABC):
@property
@abstractmethod
def my_abstract_property(self):
...
Python 2: (python docs)
class C(ABC):
@abstractproperty
def my_abst...
How to do Mercurial's 'hg remove' for all missing files?
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there is also hg forget which is eqivalent to hg rm -Af
– jk.
Mar 10 '10 at 9:32
37
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Is it safe to resolve a promise multiple times?
.... Only thing to understand is that once resolved (or rejected), that is it for a defered object - it is done.
If you should call then(...) on it's promise again, you should immediately get the (first) resolved/rejected result.
Additional calls to resolve() will not (should not?) have any effect....
Update all values of a column to lowercase
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UPDATE table_name SET tag = BINARY LOWER(tag) for case insensitive matching.
– Enyby
Jan 19 '18 at 12:39
2
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How to ignore xargs commands if stdin input is empty?
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For GNU xargs, you can use the -r or --no-run-if-empty option:
--no-run-if-empty
-r If the standard input does not contain any nonblanks, do not run the command. Normally, the command is run once even if th...
How get integer value from a enum in Rails?
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You can get the integer values for an enum from the class the enum is on:
Model.sale_infos # Pluralized version of the enum attribute name
That returns a hash like:
{ "plan_1" => 1, "plan_2" => 2 ... }
You can then use the sale_info value from ...
Use of ~ (tilde) in R programming Language
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The thing on the right of <- is a formula object. It is often used to denote a statistical model, where the thing on the left of the ~ is the response and the things on the right of the ~ are the explanatory variables. So in English you'd say something like "...