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Do declared properties require a corresponding instance variable?
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In your interface, you can formally declare an instance variable between the braces, or via @property outside the braces, or both. Either way, they become attributes of the class. The difference is that if you declare @property, then you can implement usin...
Rails params explained?
...e "1" and params[:boo] would be "octopus".
In HTTP/HTML, the params are really just a series of key-value pairs where the key and the value are strings, but Ruby on Rails has a special syntax for making the params be a hash with hashes inside. For example, if the user's browser requested
http://w...
Objective-C Static Class Level variables
...ing a Class Object in Apple's Objective-C docs.
– big_m
Oct 3 '11 at 16:02
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How can I use if/else in a dictionary comprehension?
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@Marcin's answer covers it all, but just in case someone wants to see an actual example, I add two below:
Let's say you have the following dictionary of sets
d = {'key1': {'a', 'b', 'c'}, 'key2': {'foo', 'bar'}, 'key3': {'so', 'sad'}}
and you want ...
what is the difference between 'transform' and 'fit_transform' in sklearn
...is meant for when you have already computed PCA, i.e. if you have already called its .fit method.
In [12]: pc2 = RandomizedPCA(n_components=3)
In [13]: pc2.transform(X) # can't transform because it does not know how to do it.
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Some built-in to pad a list in python
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a += [''] * (N - len(a))
or if you don't want to change a in place
new_a = a + [''] * (N - len(a))
you can always create a subclass of list and call the method whatever you please
class MyList(list):
def ljust(self, n, fillvalue=''):
return self + [fillvalue] * (n - len(self))
a...
How to have git log show filenames like svn log -v
...ncouraged to use
git-log[1] instead. The
whatchanged command is essentially the same as
git-log[1] but defaults to show
the raw format diff output and to skip merges.
The command is kept primarily for historical reasons; fingers of many
people who learned Git long before git log was i...
How to get Url Hash (#) from server side
...e with .ClientID but we found it simpler to just use the wrapper DIV as it allows all this Javascript to live in an external file and be used in a generic fashion.
If the hidden input field has a valid value, set that as the URL hash (window.location.hash again) and/or perform other actions.
We us...
How to change the foreign key referential action? (behavior)
... means that if you delete a row from the parent table (Users in this case) all referencing rows from the child table (UserDetails) are also deleted.
– edruid
Jan 11 '18 at 14:20
1
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Automapper - how to map to constructor parameters instead of property setters
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Use ConstructUsing
this will allow you to specify which constructor to use during the mapping. but then all of the other properties will be automatically mapped according to the conventions.
Also note that this is different from ConvertUsing in that con...