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Why can't I inherit static classes?
...en with static methods (as they are defined on type level). How should the compiler decide to select the method to invoke?
(littleguru)
And as a valuable idea, littleguru has a partial "workaround" for this issue: the Singleton pattern.
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How to set a Django model field's default value to a function call / callable (e.g., a date relative
...ease note that since Django 1.7, usage of lambda as default value is not recommended (c.f. @stvnw comment). The proper way to do this is to declare a function before the field and use it as a callable in default_value named arg:
from datetime import datetime, timedelta
# default to 1 day from now
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Label encoding across multiple columns in scikit-learn
....apply(LabelEncoder().fit_transform)
EDIT2:
In scikit-learn 0.20, the recommended way is
OneHotEncoder().fit_transform(df)
as the OneHotEncoder now supports string input.
Applying OneHotEncoder only to certain columns is possible with the ColumnTransformer.
EDIT:
Since this answer is over a ...
Advantage of switch over if-else statement
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Use switch.
In the worst case the compiler will generate the same code as a if-else chain, so you don't lose anything. If in doubt put the most common cases first into the switch statement.
In the best case the optimizer may find a better way to generate the...
Which is better, return value or out parameter?
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A poor an unhelpful answer. As explained in the comments on this question, out parameters have several useful advantages. Preference between out vs return should depend on the situation.
– aaronsnoswell
Dec 17 '12 at 20:55
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Static Classes In Java
...o instance methods can be called or instance fields accessed
Note that the compiler will not prevent you from declaring an instance (non-static) member. The issue will only show up if you attempt to call the instance member
Simple example per suggestions from above:
public class TestMyStaticClass...
Check if a string matches a regex in Bash script
...ate =~ ^regex$ ]] && echo "matched" || echo "did not match"
where commands after && are executed if the test is successful, and commands after || are executed if the test is unsuccessful.
Note this is based on the solution by Aleks-Daniel Jakimenko in User input date format verifica...
Should a retrieval method return 'null' or throw an exception when it can't produce the return value
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community wiki
Ken
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How to delete a stash created with git stash create?
... stash create. From the docs:
Create a stash entry (which is a regular commit object) and return its object name, without storing it anywhere in the ref namespace. This is intended to be useful for scripts. It is probably not the command you want to use; see "save" above.
Since nothing referen...
Can modules have properties the same way that objects can?
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