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Operation on every pair of element in a list
...differ:
product() generates every possible pairing of elements, including all duplicates:
1,1 1,2 1,3 1,4
2,1 2,2 2,3 2,4
3,1 3,2 3,3 3,4
4,1 4,2 4,3 4,4
permutations() generates all unique orderings of each unique pair of elements, eliminating the x,x duplicates:
. 1,2 1,3 1,4...
differentiate null=True, blank=True in django
When we add a database field in django we generally write:
18 Answers
18
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How can I access getSupportFragmentManager() in a fragment?
...
You can directly call
getFragmentManager()
to get the fragment manager.
or
In your fragment,
Create field :
private FragmentActivity myContext;
override onAttach method of your fragment :
@Override
public void onAttach(Activity ...
Remove or uninstall library previously added : cocoapods
...en by Kyle Fuller - deintegrate, I'll post the proper workflow here:
Install clean:
$ sudo gem install cocoapods-clean
Run deintegrate in the folder of the project:
$ pod deintegrate
Clean:
$ pod clean
Modify your podfile (delete the lines with the pods you don't want to use anymore) and run...
How can I get pg_dump to authenticate properly
...ing host variable PGPASSWORD and .pgpass and neither of these two will allow me to authenticate to the database. I have chmod 'd .pgpass to appropriate permissions and also tried:
...
advantage of tap method in ruby
...= User.new
user.username = "foobar"
user.save!
they would have to follow all the three lines and then recognize that it is just creating an instance named user.
If it were:
user = User.new.tap do |u|
u.username = "foobar"
u.save!
end
then that would be immediately clear. A reader would not...
Removing empty lines in Notepad++
...g like a regular expression.
You have to be in Extended mode
If you want all the lines to end up on a single line use \r\n. If you want to simply remove empty lines, use \n\r as @Link originally suggested.
Replace either expression with nothing.
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Is Haxe worth learning? [closed]
...atform API, they can be reused from platform to platform with no effort at all. All the platforms also share common APIs like XML access, HTTP connections and reflection. Platforms that have things in common (i.e. Neko and PHP) share the same API for things like file access or web-server development...
Can I concatenate multiple MySQL rows into one field?
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My need was to get ALL the data from one column. Don't use the GROUP BY clause to do this. Example : SELECT GROUP_CONCAT(emails SEPARATOR ', ') FROM users;
– Jonathan Bergeron
Jan 17 '14 at 14:04
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How to get Resource Name from Resource id
... wouldn't recommend use it if you use Proguard (minifyEnabled true), especially for getResources().getIdentifier(...
– user25
Jul 14 '18 at 22:54
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