Conditional statements in a class, but outside of scope of the function
The class body is just Python code. It has specific scope rules, but anything goes otherwise. This means you can create functions conditionally:
class C:
if some_condition:
def optional_method(self):
pass
or pull methods from elsewhere:
import some_module
class D:
method_name = some_module.function_that_accepts_self
etc.
The Python documentation for class
definitions states:
A class definition is an executable statement.
and
The class’s suite is then executed in a new execution frame (see section Naming and binding), using a newly created local namespace and the original global namespace. (Usually, the suite contains only function definitions.) When the class’s suite finishes execution, its execution frame is discarded but its local namespace is saved. A class object is then created using the inheritance list for the base classes and the saved local namespace for the attribute dictionary.
Note the usually in that text. Essentially, the class body is executed as a function would, and anything you put in the body namespace becomes an attribute on the class.
The Naming and binding section then tells you:
The scope of names defined in a class block is limited to the class block; it does not extend to the code blocks of methods
so names you define in this block cannot be directly accessed in methods; you'd use class.name
or self.name
instead.
In java everything is classes
and object
, classes
are container but in python everything is object
.
Classes
are also objects
. like functions(also objects)
so when you use conditional statement in function then python allows you to do same in Classes.
like:-
def A():
if condition:
do something
elif condition:
do somethig
else:
do something
is same
Class A()
if condition:
do something
elif condition:
do somethig
else:
do something
you can assign functions even to store in a variable like you do for classes
def A():
pass
a = A # is valid
while in java you can't define function outside the classes.