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Django migration strategy for renaming a model and relationship fields
...n files (!).
Update: As ceasaro mentions, newer versions of Django are usually able to detect and ask if a model is renamed. So try manage.py makemigrations first and then check the migration file.
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How to avoid “if” chains?
...ep<X>() should evaluate only if the previous one succeeded (this is called short circuit evaluation)
executeThisFunctionInAnyCase() will be executed in any case
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How do multiple clients connect simultaneously to one port, say 80, on a server? [duplicate]
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First off, a "port" is just a number. All a "connection to a port" really represents is a packet which has that number specified in its "destination port" header field.
Now, there are two answers to your question, one for stateful protocols and one for stateless...
Indent multiple lines quickly in vi
... the pasted block with the surrounding text.
Also, the shiftwidth setting allows you to control how many spaces to indent.
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How to make a class JSON serializable
...t;>> magic(f)
'{"fname": "/foo/bar"}'
In that case you can merely call json.dumps(f.__dict__).
If you want more customized output then you will have to subclass JSONEncoder and implement your own custom serialization.
For a trivial example, see below.
>>> from json import JSONE...
Convert nested Python dict to object?
...; s.a
1
>>> s.b
{'c': 2}
>>> s.c
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'MyStruct' object has no attribute 'c'
>>> s.d
['hi']
The alternative (original answer contents) is:
class Struct:
def __init__(self...
Getter and Setter?
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That's not really setter and getter. Typically I need for each property different implementation of getter!
– sumid
Feb 16 '13 at 0:59
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Get name of object or class
...(function(){}); new myclass prints myclass {}
– Hugh Allen
May 26 '14 at 4:09
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Ruby send vs __send__
...ss being manipulated defines. It could have overriden send.
Watch:
class Foo
def bar?
true
end
def send(*args)
false
end
end
foo = Foo.new
foo.send(:bar?)
# => false
foo.__send__(:bar?)
# => true
If you override __send__, Ruby will emit a warning:
warning: redefining ...
What are good uses for Python3's “Function Annotations”
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I think this is actually great.
Coming from an academic background, I can tell you that annotations have proved themselves invaluable for enabling smart static analyzers for languages like Java. For instance, you could define semantics like sta...