Obs:当然我可以创建一个验证方法,并在我所有其他方法中调用此方法。但我想知道做一些我一直想的事情是否可行。
我需要的:
我有一个类,我的所有方法都应验证它接收的参数(一个对象)是否为None,以及它是否具有特定方法。让我们简单一点。
我想知道是否有类似以下代码的简单内容。
这是一个例子:
def validate(obj):
return not obj or obj.can_validate()
class MyClass:
def __init__(self):
pass
@validate(obj)
def my_method_1(self, obj):
print(obj)
@validate(obj)
def my_method_2(self, obj):
print(obj)
@validate(obj)
def my_method_3(self, obj):
print(obj)
class Validator1:
def __init__(self):
pass
class Validator2:
def __init__(self):
pass
def can_validate(self):
pass
my_class = MyClass()
obj_1 = None
obj_2 = Validator1()
obj_3 = Validator2()
print(x.my_method_1(obj_1))
print(x.my_method_2(obj_2))
print(x.my_method_3(obj_3))
# The output would be something like this>>
# output:
# <empty line because obj_1 is None>
# <empty line because obj_2 has no method can_validate()>
# __Class__...something <since it's not none and has can_validate() method>
如果没有类似的东西,最干净和正确的方法应该是什么,避免代码重复和“大量代码”?
只需对现有代码进行最少的更改:
def validate(func):
def modified(self, obj):
if obj and hasattr(obj, 'can_validate'):
return func(self, obj)
return None # None will be printed. Change it to '' to print empty line
return modified
class MyClass:
def __init__(self):
pass
@validate
def my_method_1(self, obj):
print(obj)
@validate
def my_method_2(self, obj):
print(obj)
@validate
def my_method_3(self, obj):
print(obj)
class Validator1:
def __init__(self):
pass
class Validator2:
def __init__(self):
pass
def can_validate(self):
pass
x = MyClass()
obj_1 = None
obj_2 = Validator1()
obj_3 = Validator2()
print(x.my_method_1(obj_1))
print(x.my_method_2(obj_2))
print(x.my_method_3(obj_3))
输出:
None
None
<__main__.Validator2 object at 0x7f6185ca9e10>
None