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django: BooleanField, how to set the default value to true?
...anField(default=True)
Finally, if you want to dynamically choose at runtime whether or not your field will be selected by default, you can use the initial parameter to the form when you initialize it:
form = MyForm(initial={'my_field':True})
...
Pointer to class data member “::*”
I came across this strange code snippet which compiles fine:
15 Answers
15
...
Code Golf: Collatz Conjecture
...--> 5 --> 16 --> 8 --> 4 --> 2 --> 1
;
; There's even some error checking involved:
; >> $ ./collatz
; >> Usage: ./collatz NUMBER
;
section .text
global main
extern printf
extern atoi
main:
cmp dword [esp+0x04], 2
jne .usage
mov ebx, [esp+0x08]
push dword [e...
Red black tree over avl tree
...s and they support insertion, deletion and look-up in guaranteed O(logN) time. However, there are following points of comparison between the two:
AVL trees are more rigidly balanced and hence provide faster look-ups. Thus for a look-up intensive task use an AVL tree.
For an insert intensive tasks,...
How do I determine whether my calculation of pi is accurate?
I was trying various methods to implement a program that gives the digits of pi sequentially. I tried the Taylor series method, but it proved to converge extremely slowly (when I compared my result with the online values after some time). Anyway, I am trying better algorithms.
...
Convert Rows to columns using 'Pivot' in SQL Server
...e correct code using a hard-coded version initially.
First up, here are some quick table definitions and data for use:
CREATE TABLE #yt
(
[Store] int,
[Week] int,
[xCount] int
);
INSERT INTO #yt
(
[Store],
[Week], [xCount]
)
VALUES
(102, 1, 96),
(101, 1, 138),
(105, 1, 3...
Authorize Attribute with Multiple Roles
...les = string.Join(",", roles);
}
}
Assuming your roles will be the same for multiple controllers, create a helper class:
public static class Role
{
public const string Administrator = "Administrator";
public const string Assistant = "Assistant";
}
Then use it like so:
public class ...
Python - When to use file vs open
...
You should always use open().
As the documentation states:
When opening a file, it's preferable
to use open() instead of invoking this
constructor directly. file is more
suited to type testing (for example,
writing "isinstance(f, file)").
Also, file() ...
Regular expression for exact match of a string
...p you:
/^123456$/
in perl the test for matching the password would be something like
print "MATCH_OK" if ($input_pass=~/^123456$/);
EDIT:
bart kiers is right tho, why don't you use a strcmp() for this? every language has it in its own way
as a second thought, you may want to consider a safer...
Confusion between factor levels and factor labels
...f a factor in R.
Up to now, I always thought that levels were the 'real' name of factor levels, and labels were the names used for output (such as tables and plots). Obviously, this is not the case, as the following example shows:
...