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correct way to define class variables in Python [duplicate]
... being init always executed after the object is created, it becomes practically equal to define variables outside of init, right?
– jeanc
Jan 29 '12 at 21:33
2
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Comparing strings with == which are declared final in Java
...nal and initialized with a compile-time constant expression (§15.28), is called a constant variable.
Also from JLS §15.28 - Constant Expression:
Compile-time constant expressions of type String are always "interned" so as to share unique instances, using the method String#intern().
This ...
How to identify numpy types in python?
...o test for that. And so on. The point is, you have to know what you're actually asking for when you want to do something as unusual as loose manual type switching, but once you know, it's easy to implement.
– abarnert
Mar 11 '16 at 20:41
...
how to use javascript Object.defineProperty
...rs = new Product("Sneakers",20);
sneakers.discount = 50; // 50, setter is called
sneakers.discount+= 20; // 70, setter is called
sneakers.discount+= 20; // 80, not 90!
alert(sneakers.discount); // getter is called
Note the last but one line: the responsibility for correct discount value was moved ...
Determine if variable is defined in Python [duplicate]
...ime? This is not always obvious because (1) the variable could be conditionally set, and (2) the variable could be conditionally deleted. I'm looking for something like defined() in Perl or isset() in PHP or defined? in Ruby.
...
How do I replace whitespaces with underscore?
...s, such as \t or a non-breaking space.
– Roberto Bonvallet
Jun 17 '09 at 15:49
13
Yes you are cor...
Ignore python multiple return value
...add gettext functionality to someone else's code (that defines a function called '_') so it should be banned
– nosklo
Jan 11 '09 at 13:32
28
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How to search a specific value in all tables (PostgreSQL)?
... at 11:55
Mike Sherrill 'Cat Recall'Mike Sherrill 'Cat Recall'
78.5k1616 gold badges103103 silver badges156156 bronze badges
...
How to redirect to a 404 in Rails?
...ou want to show a 404 page, create a render_404 method (or not_found as I called it) in ApplicationController like this:
def not_found
raise ActionController::RoutingError.new('Not Found')
end
Rails also handles AbstractController::ActionNotFound, and ActiveRecord::RecordNotFound the same way....
SQLAlchemy: cascade delete
...use that is where you defined your relationship (it doesn't care that you called it "Child" of course).
If you define the relationship on the Parent class instead, it will work:
children = relationship("Child", cascade="all,delete", backref="parent")
(note "Child" as a string: this is allowed wh...