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When should I use uuid.uuid1() vs. uuid.uuid4() in python?
...d4() generates, as you said, a random UUID. The chance of a collision is really, really, really small. Small enough, that you shouldn't worry about it. The problem is, that a bad random-number generator makes it more likely to have collisions.
This excellent answer by Bob Aman sums it up nicely. (I...
Unique ways to use the Null Coalescing operator [closed]
...
Well, first of all, it's much easier to chain than the standard ternary:
string anybody = parm1 ?? localDefault ?? globalDefault;
vs.
string anyboby = (parm1 != null) ? parm1
: ((localDefault != null) ? localDefault
...
delete map[key] in go?
...sions = map[string] chan int{};
sessions["moo"] = make (chan int);
_, ok := sessions["moo"];
if ok {
delete(sessions, "moo");
}
}
share
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AngularJS : Prevent error $digest already in progress when calling $scope.$apply()
I'm finding that I need to update my page to my scope manually more and more since building an application in angular.
28 A...
SQLAlchemy default DateTime
... This isn't right. The timestamp at model load will be used for all new records rather than the time the record is added.
– SkyLeach
Feb 9 '16 at 16:18
10
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Doctrine and composite unique keys
...straint;
/**
* Common\Model\Entity\VideoSettings
*
* @Table(name="video_settings",
* uniqueConstraints={
* @UniqueConstraint(name="video_unique",
* columns={"video_dimension", "video_bitrate"})
* }
* )
* @Entity
*/
See @UniqueConstraint
...
Perform an action in every sub-directory using Bash
... command, this is more concise:
for D in *; do [ -d "${D}" ] && my_command; done
Or an even more concise version (thanks @enzotib). Note that in this version each value of D will have a trailing slash:
for D in */; do my_command; done
...
Using Vim's persistent undo?
...eep undo history across sessions by storing it in a file
if has('persistent_undo')
let myUndoDir = expand(vimDir . '/undodir')
" Create dirs
call system('mkdir ' . vimDir)
call system('mkdir ' . myUndoDir)
let &undodir = myUndoDir
set undofile
endif
...
In HTML I can make a checkmark with ✓ . Is there a corresponding X-mark?
... Not the comprehensive list, but a start at w3schools.com/tags/ref_symbols.asp
– Bill the Lizard
Apr 3 '09 at 0:44
5
...
常用Sql - 爬虫/数据库 - 清泛IT社区，为创新赋能！
...) NOT NULL COMMENT '递增ID',
`FIELD_1` varchar(32) NOT NULL COMMENT '字段1',
`FIELD_2` ...