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Comma separator for numbers in R?
... if you have a vector this can go awry if the numebrs are quite different. From help "Numeric vectors are encoded with the minimum number of decimal places needed to display all the elements to at least the digits significant digits. However, if all the elements then have trailing zeroes, the number...
Ruby on Rails: Delete multiple hash keys
...uces potential security issues. A good rule of thumb for handling any data from visitors is to use a whitelist approach. In this case, using Hash#slice instead.
params.slice!(:param_to_remove_1, :param_to_remove_2)
redirect_to my_path(params)
...
Python string.join(list) on object array rather than string array
...
(another) +1: coming from the Perl world this is the most common thing in the universe: join("sep", list) - and all elements of list get converted to their string representations. I've been really struggling to find a solution in python.
...
How to run cron once, daily at 10pm
...t I look at everytime I am writing a new crontab entry:
To start editing from terminal -type:
zee$ crontab -e
what you will add to crontab file:
0 22 * * 0 some-user /opt/somescript/to/run.sh
What it means:
[
+ user => 'some-user',
+ minute => ‘0’, <<= ...
What are Scala context and view bounds?
...o f doesn't need to know about it.
Besides Ordered, the most common usage from the library is handling String and Array, which are Java classes, like they were Scala collections. For example:
def f[CC <% Traversable[_]](a: CC, b: CC): CC = if (a.size < b.size) a else b
If one tried to do t...
How to set UICollectionViewDelegateFlowLayout?
...ew.delegate = self;. Note that UICollectionViewDelegateFlowLayout inherits from UICollectionViewDelegate.
I admit it caught me off guard at first.
Oh and this will only work if self.collectionView.collectionViewLayout is actually set to your flow layout. (or set with initWithFrame:collectionViewLayo...
How to `go test` all tests in my project?
...
From Go 1.9 onwards, use
go test ./...
In Go 1.6 through 1.8, the ./... matched also the vendor directory. To skip vendored packages, you'd use
go test $(go list ./... | grep -v /vendor/)
Sources: https://github.com/gol...
Understanding Fragment's setRetainInstance(boolean)
... to saved orientation changing Time.Say I have download a bunch of Bitmaps from server and each one is 1MB, when the user accidentally rotate his device, I certainly don't want to do all the download work again.So I create a Fragment holding my bitmaps and add it to the manager and call setRetainIns...
Rails - Validate Presence Of Association?
...ciations with validates_existence_of (which is a plugin):
Example snippet from this blog entry:
class Tagging < ActiveRecord::Base
belongs_to :tag
belongs_to :taggable, :polymorphic => true
validates_existence_of :tag, :taggable
belongs_to :user
validates_existence_of :user, :allo...
How can I add items to an empty set in python
...Set.
The update method in dictionary is used to update the new dictionary from a previous one, like so,
>>> abc = {1: 2}
>>> d.update(abc)
>>> d
{1: 2}
Whereas in sets, it is used to add elements to the set.
>>> D.update([1, 2])
>>> D
set([1, 2])
...