- testsuite相关代码中，描述符类装饰器比较难以理解，简化源码方便理解如下
'''robot 源码解读3【testsuite相关】
目的：
1. 查看类的继承关系
2. setter类的理解
'''
# 描述符类, 描述符是作为类的属性而不是实例属性存在的
# 将一个类中的方法装饰成类中的属性
class setter(object):
def __init__(self, method):
self.method = method
self.attr_name = '_setter__' + method.__name__
self.__doc__ = method.__doc__
print('setter: __init__:' ,method)
def __get__(self, instance, owner): # instance：TestSuite object ；owner：class TestSuite
if instance is None:
return self
print('setter: __get__:', instance, owner)
return getattr(instance, self.attr_name) # 返回的是TestSuite的attr_name
# try:
# print('setter: __get__:', instance, owner)
# return getattr(instance, self.attr_name)
# except AttributeError:
# raise AttributeError(self.method.__name__)
def __set__(self, instance, value):
if instance is None:
return
print('setter: __set__:', instance,value )
# 相当于TestSuite 执行 test(self, Keyword)
setattr(instance, self.attr_name, self.method(instance, value))
class SetterAwareType(type):
def __new__(cls, name, bases, dct):
slots = dct.get('__slots__')
if slots is not None:
for item in dct.values():
if isinstance(item, setter):
slots.append(item.attr_name)
return type.__new__(cls, name, bases, dct)
def with_metaclass(meta, *bases):
"""Create a base class with a metaclass."""
# This requires a bit of explanation: the basic idea is to make a
# dummy metaclass for one level of class instantiation that replaces
# itself with the actual metaclass.
class metaclass(type):
def __new__(cls, name, this_bases, d):
return meta(name, bases, d)
return type.__new__(metaclass, 'temporary_class', (), {})
class ModelObject(with_metaclass(SetterAwareType, object)):
__slots__ = [] # __slots__变量，来限制该class实例能添加的属性
def copy(self, **attributes):
pass
class Keyword(ModelObject):
@setter
def parent(self, parent):
"""Parent test suite, test case or keyword."""
if parent and parent is not self.parent:
self._sort_key = getattr(parent, '_child_sort_key', -1)
return parent
@setter
def tags(self, tags):
"""Keyword tags as a :class:`~.model.tags.Tags` object."""
return tags
class TestSuite(ModelObject):
def __init__(self, name='', doc='', metadata=None, source=None):
self.parent = None #: Parent suite. ``None`` with the root suite.
self._name = name
# test = setter(test) , setter是描述符类，描述符是作为类的属性而不是实例属性存在的
@setter
def test(self, Keyword):
print('TestSuite: test: 赋值的时候调用',Keyword)
return Keyword
# _setter__test = 'amize'
# 源码中都是如下的suites，tests，keywords等
# @setter
# def suites(self, suites):
# """Child suites as a :class:`~.TestSuites` object."""
# return TestSuites(self.__class__, self, suites)
#
# @setter
# def tests(self, tests):
# """Tests as a :class:`~.TestCases` object."""
# return TestCases(self.test_class, self, tests)
#
# @setter
# def keywords(self, keywords):
# """Suite setup and teardown as a :class:`~.Keywords` object."""
# return Keywords(self.keyword_class, self, keywords)
''' 以下不实例化也会打印
setter: __init__: <function Keyword.parent at 0x0000020B824D7E58>
setter: __init__: <function Keyword.tags at 0x0000020B824D7EE8>
setter: __init__: <function TestSuite.test at 0x0000020B82520048>'''
# 不执行下面的语句也会打印上面的
suite = TestSuite('name')
keyword = Keyword()
# @setter 保证suite.test必须赋值后才能运用，因为__get__ 返回的是__init__里面的值
# print(suite.test) # 这里会报错：'TestSuite' object has no attribute '_setter__test'
# print(suite._setter__test) # 同上，报错：'TestSuite' object has no attribute '_setter__test'
suite.test = keyword # 【1. setter: __set__：函数】 ，【2. TestSuite: test: 函数被调用】
# 已经赋值了 suite.test = keyword ，不能看class setter中的 __init__了，这里会报错：'Keyword' object has no attribute 'method'
# print(type(suite.test.method))
# _setter__test == suite.test ,区别是 print(suite.test)还要调用__get__
print(suite._setter__test)
print(suite.test) # 【1. setter: __get__ 调用】
print(suite.__dict__) # {'parent': None, '_name': 'name', '_setter__test': <__main__.Keyword object at 0x0000026458EF11C8>}
print(dir(suite))