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Declaring variables inside or outside of a loop
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The scope of local variables should always be the smallest possible.
In your example I presume str is not used outside of the while loop, otherwise you would not be asking the question, because declaring it inside the while loop would not be an option, since it would not comp...
How do I filter query objects by date range in Django?
...year='2011',
date__month='01')
Edit
As Bernhard Vallant said, if you want a queryset which excludes the specified range ends you should consider his solution, which utilizes gt/lt (greater-than/less-than).
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Instance attribute attribute_name defined outside __init__
I split up my class constructor by letting it call multiple functions, like this:
6 Answers
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How are Python's Built In Dictionaries Implemented?
...e).
Python dictionaries are implemented as hash tables.
Hash tables must allow for hash collisions i.e. even if two distinct keys have the same hash value, the table's implementation must have a strategy to insert and retrieve the key and value pairs unambiguously.
Python dict uses open addressin...
Forced naming of parameters in Python
...(10, forcenamed=20)
10 20
>>> foo(10, 20)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: foo() takes exactly 1 positional argument (2 given)
This can also be combined with **kwargs:
def foo(pos, *, forcenamed, **kwargs):
...
Split views.py in several files
...__.py use *, like this:
from viewsa import *
from viewsb import *
I actually don't know about speed issues (but I doubt there are any).
For Models it might be a bit difficult.
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How can I open multiple files using “with open” in Python?
I want to change a couple of files at one time, iff I can write to all of them. I'm wondering if I somehow can combine the multiple open calls with the with statement:
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How to add property to a class dynamically?
...ing on. Better late than never.
You can add a property to a class dynamically. But that's the catch: you have to add it to the class.
>>> class Foo(object):
... pass
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>>> foo = Foo()
>>> foo.a = 3
>>> Foo.b = property(lambda self: self.a + 1)
>>&...
Is False == 0 and True == 1 an implementation detail or is it guaranteed by the language?
.....] Boolean values behave like the values 0 and 1, respectively, in almost all contexts, the exception being that when converted to a string, the strings "False" or "True" are returned, respectively.
There is also, for Python 2:
In numeric contexts (for example when used as the argument to an ...
Why is __init__() always called after __new__()?
... new instance.
__new__ is the first step of instance creation. It's called first, and is
responsible for returning a new
instance of your class.
In contrast,
__init__ doesn't return anything; it's only responsible for initializing the
instance after it's been created.
In ge...