def hasattr(*args, **kwargs): """Return whether the object has an attribute with the given name.This is done by calling getattr(obj, name) and catching AttributeError."""pass

def getattr(object, name, default=None): """getattr(object, name[, default]) -> valueGet a named attribute from an object; getattr(x, 'y') is equivalent to x.y.When a default argument is given, it is returned when the attribute doesn'texist; without it, an exception is raised in that case."""pass

def setattr(x, y, v):"""Sets the named attribute on the given object to the specified value.setattr(x, 'y', v) is equivalent to ``x.y = v''"""pass

def delattr(x, y): """Deletes the named attribute from the given object.delattr(x, 'y') is equivalent to ``del x.y''"""pass

class PoloBlog:sum = 0def __init__(self, name):self.name = namedef test(self):print("====姓名==== ", self.name)

blog = PoloBlog("小菠萝")
# hasattr
print(hasattr(blog, "name"))        # 实例对象-实例属性
print(hasattr(blog, "sum"))         # 实例对象-类属性
print(hasattr(PoloBlog, "sum"))     # 类对象-类属性
print(hasattr(PoloBlog, "name"))    # 类对象-实例属性# 输出结果
True
True
True
False

# getattr
print(getattr(blog, "name"))  # 实例对象-实例属性
print(getattr(blog, "sum"))  # 实例对象-类属性
print(getattr(PoloBlog, "sum"))  # 类对象-类属性
print(getattr(PoloBlog, "name", "默认值"))  # 类对象-实例属性# 输出结果
小菠萝
0
0
默认值

# 设置一个新的实例属性
setattr(blog, "age", 24)# 设置一个新的实例方法
setattr(blog, "printNameAge", lambda self: f"姓名：{self.name} 年龄：{self.age}")print(blog.__dict__)
print(blog.printNameAge(blog))# 输出结果
{'name': '小菠萝', 'age': 24, 'printNameAge': <function <lambda> at 0x10391a1f0>}
姓名：小菠萝 年龄：24

# delattr
delattr(blog, "age")
delattr(blog, "printNameAge")
print(blog.__dict__)# 输出结果
{'name': '小菠萝'}

sums = 0def test1():print("test")class A():passthis_module = sys.modules[__name__]
print(__name__)
print(this_module)print(hasattr(this_module, "sums"))  # 变量
print(hasattr(this_module, "test1"))  # 方法
print(hasattr(this_module, "A"))  # 类# 输出结果
__main__
<module '__main__' from '/Users/polo/Documents/pylearn/第四章：面向对象/22_反射.py'>True
True
True

True
反射22222
小菠萝 

class Web:def login(self):print('欢迎来到登录页面')def register(self):print('欢迎来到注册页面')def save(self):print('欢迎来到存储页面')while True:obj = Web()choose = input(">>>").strip()if choose == 'login':obj.login()elif choose == 'register':obj.register()elif choose == 'save':obj.save()

class Web:def login(self):print('欢迎来到登录页面')def register(self):print('欢迎来到注册页面')def save(self):print('欢迎来到存储页面')while True:obj = Web()choose = input(">>>").strip()# 判断对象是否有对应的方法if hasattr(obj, choose):# 获取对应的方法f = getattr(obj, choose)# 执行方法f()

class BaseRequest:req = requests.Session()def get(self, url):resp = self.req.get(url)print("==get==")return respdef post(self, url):resp = self.req.post(url)print("==post==")return respdef put(self, url):resp = self.req.put(url)print("==put==")return resp# 不使用反射的方法def main(self, method, url):if method == "get":self.get(url)elif method == "post":self.post(url)elif method == "put":self.put(url)

    # 使用反射的方法def main_attr(self, method, url):if hasattr(self, method):func = getattr(self, method)func(url)

request = BaseRequest()
# 不使用反射
request.main("get", "http://www.baidu.com")
request.main("post", "http://www.baidu.com")
request.main("put", "http://www.baidu.com")# 使用反射
request.main_attr("get", "http://www.baidu.com")
request.main_attr("post", "http://www.baidu.com")
request.main_attr("put", "http://www.baidu.com")# 输出结果
==get==
==post==
==put====get==
==post==
==put==