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How is __eq__ handled in Python and in what order?
....x sees a == b, it tries the following.
If type(b) is a new-style class, and type(b) is a subclass of type(a), and type(b) has overridden __eq__, then the result is b.__eq__(a).
If type(a) has overridden __eq__ (that is, type(a).__eq__ isn't object.__eq__), then the result is a.__eq__(b).
If type(...
Foreign Key to non-primary key
I have a table which holds data, and one of those rows needs to exist in another table. So, I want a foreign key to maintain referential integrity.
...
Build a Basic Python Iterator
...ator protocol, which basically means they provide two methods: __iter__() and __next__().
The __iter__ returns the iterator object and is implicitly called
at the start of loops.
The __next__() method returns the next value and is implicitly called at each loop increment. This method raises a...
Iterating through a range of dates in Python
...e in (start_date + timedelta(n) for n in range(day_count)):
print ...
And no list gets stored, only one generator is iterated over. Also the "if" in the generator seems to be unnecessary.
After all, a linear sequence should only require one iterator, not two.
Update after discussion with John M...
Rails: Using build with a has_one association in rails
...
The build method signature is different for has_one and has_many associations.
class User < ActiveRecord::Base
has_one :profile
has_many :messages
end
The build syntax for has_many association:
user.messages.build
The build syntax for has_one association:
user.bu...
Bash continuation lines
...; "lines"
continuation lines
If this creates two arguments to echo and you only want one, then let's look at string concatenation. In bash, placing two strings next to each other concatenate:
$ echo "continuation""lines"
continuationlines
So a continuation line without an indent is one w...
How do I execute code AFTER a form has loaded?
...uently minimizing, maximizing, restoring, hiding, showing, or invalidating and repainting will not raise this event."
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is there a Java equivalent to null coalescing operator (??) in C#? [duplicate]
... answered Mar 7 '11 at 17:36
Andrzej DoyleAndrzej Doyle
95.5k2929 gold badges181181 silver badges224224 bronze badges
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Learning to write a compiler [closed]
Preferred languages : C/C++, Java, and Ruby.
38 Answers
38
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Returning a C string from a function
...Other languages (Java, Pascal, etc.) use different methodologies to understand "my string".
If you ever use the Windows API (which is in C++), you'll see quite regularly function parameters like: "LPCSTR lpszName". The 'sz' part represents this notion of 'string-zero': an array of bytes with a null...