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Django CharField vs TextField
...the difference between CharField() and TextField() in Django? The documentation says that CharField() should be used for smaller strings and TextField() should be used for larger strings. Okay, but where is the line drawn between "small" and "large"? What's going on under the hood here ...
How to refer to relative paths of resources when working with a code repository
...Try to use a filename relative to the current files path. Example for './my_file':
fn = os.path.join(os.path.dirname(__file__), 'my_file')
In Python 3.4+ you can also use pathlib:
fn = pathlib.Path(__file__).parent / 'my_file'
...
What is dynamic programming? [closed]
...ith dynamic programming, you store your results in some sort of table generally. When you need the answer to a problem, you reference the table and see if you already know what it is. If not, you use the data in your table to give yourself a stepping stone towards the answer.
The Cormen Algorithms ...
Create a tar.xz in one command
...
Use the -J compression option for xz. And remember to man tar :)
tar cfJ <archive.tar.xz> <files>
Edit 2015-08-10:
If you're passing the arguments to tar with dashes (ex: tar -cf as opposed to tar cf), then th...
Why do you need to create a cursor when querying a sqlite database?
I'm completely new to Python's sqlite3 module (and SQL in general for that matter), and this just completely stumps me. The abundant lack of descriptions of cursor objects (rather, their necessity) also seems odd.
...
How to create default value for function argument in Clojure
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A function can have multiple signatures if the signatures differ in arity. You can use that to supply default values.
(defn string->integer
([s] (string->integer s 10))
([s base] (Integer/parseInt s base)))
Note t...
Rails has_and_belongs_to_many migration
I have two models restaurant and user that I want to perform a has_and_belongs_to_many relationship.
4 Answers
...
'is' versus try cast with null check
...ing)
{
var x = (string) o;
}
This translates to the following IL:
IL_0000: nop
IL_0001: ldstr "test"
IL_0006: stloc.0 // o
IL_0007: ldloc.0 // o
IL_0008: isinst System.String
IL_000D: ldnull
IL_000E: cgt.un
IL_0010: stloc.1
IL_0011: ldloc....
What does principal end of an association means in 1:1 relationship in Entity framework
...
In one-to-one relation one end must be principal and second end must be dependent. Principal end is the one which will be inserted first and which can exist without the dependent one. Dependent end is the one which must be inserted after the principal becau...
Passing an integer by reference in Python
...d you can't just assign the "variable" a new value because then you're actually creating a new object (which is distinct from the old one) and giving it the name that the old object had in the local namespace.
Usually the workaround is to simply return the object that you want:
def multiply_by_2(x...