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How to limit the maximum value of a numeric field in a Django model?
...ormer can be restricted to the number of decimal places stored and the overall number of characters stored, is there any way to restrict it to storing only numbers within a certain range, e.g. 0.0-5.0 ?
...
What is the difference between class and instance methods?
...hen be used like so:
[MyClass aClassMethod];
MyClass *object = [[MyClass alloc] init];
[object anInstanceMethod];
Some real world examples of class methods are the convenience methods on many Foundation classes like NSString's +stringWithFormat: or NSArray's +arrayWithArray:. An instance method...
What is the definition of “interface” in object oriented programming
... one of the more overloaded and confusing terms in development.
It is actually a concept of abstraction and encapsulation. For a given "box", it declares the "inputs" and "outputs" of that box. In the world of software, that usually means the operations that can be invoked on the box (along with ar...
What is the syntax rule for having trailing commas in tuple definitions?
...
In all cases except the empty tuple the comma is the important thing. Parentheses are only required when required for other syntactic reasons: to distinguish a tuple from a set of function arguments, operator precedence, or to a...
Django TemplateDoesNotExist?
... assuming that you have the apps configured in settings.py like this:
INSTALLED_APPS = (
'appname1',
'appname2',
'appname3',
)
By default Django will load the templates under templates/ directory under every installed apps. So with your directory structure, we want to move our templat...
Pandas conditional creation of a series/dataframe column
...
List comprehension is another way to create another column conditionally. If you are working with object dtypes in columns, like in your example, list comprehensions typically outperform most other methods.
Example list comprehension:
df['color'] = ['red' if x == 'Z' else 'green' for x in d...
Is there a math nCr function in python? [duplicate]
... @Renato: what are you talking about? This answer isn't dangerous at all. Do you think that math.factorial returns a float, and not an arbitrary-precision integer, maybe?
– DSM
Mar 25 '13 at 19:03
...
Very Long If Statement in Python [duplicate]
...ther_long_identifier and
here_is_another_long_identifier != and_finally_another_long_name):
# ... your code here ...
pass
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How to convert ActiveRecord results into an array of hashes
...d objects to Ruby Hashes despite its name
tasks_records = TaskStoreStatus.all
tasks_records = tasks_records.as_json
# You can now add new records and return the result as json by calling `to_json`
tasks_records << TaskStoreStatus.last.as_json
tasks_records << { :task_id => 10, :sto...
Maven skip tests
...ependency may look as follows:
<dependency>
<groupId>com.foo</groupId>
<artifactId>A</artifactId>
<type>test-jar</type> <!-- I'm not sure if there is such a thing in Maven 2, but there is definitely a way to achieve such dependency in Mave...