Python-判断变量类型和继承链-type isinstance
阅读原文时间:2023年07月08日阅读:4

  在很多情况下,需要对类型进程动态判断,因为不同的数据类型不能互相做运算并且各自拥有不同的运算逻辑,所有需要判断对象的类型,常用的是type和isinstance,type更过用于获取对象是什么类型构建的,而isinstance可以判断对象是否继承某个类或对象是否是多个类型中的一个。

变量类型判断

  type      只能一次判断一种类型,核心是判断实例对象是由什么类型构建

  isinstance    可以判断一种类型也可以判断多种类型,同时还可以判断继承链

__author_ = "北门吹雪"
__blog__ = "http://www.cnblogs.com/2bjiujiu/"
__email__ = "422083556@qq.com"

def check_type(value):
"""使用isinstance判断变量单个类型"""
# 判断变量单个类型,如果是则返回其类型对应的字符
if isinstance(value, int):
return "int"
elif isinstance(value, float):
return "float"
elif isinstance(value, bool):
return "bool"
elif isinstance(value, str):
return "str"
elif isinstance(value, list):
return "list"
elif isinstance(value, tuple):
return "tuple"
elif isinstance(value, set):
return "set"
elif isinstance(value, dict):
return "dict"
# 如果都不是则返回不知道
else:
return "Unknow Type of {value}".format(value=value)

def check_object(value):
"""使用instance同时判断多个类型"""
# 判断变量是否是数字类型
if isinstance(value, (int, float, bool)):
return "number"
# 判断变量是否有序序列
elif isinstance(value, (str, list, tuple)):
return "Ordered sequence"
# 判断变量是否是无序序列
elif isinstance(value, (set, dict)):
return "Disordered sequence"
else:
return "Unknow Object of {value}".format(value=value)

def use_type(value):
"""type只能判断变量单个类型,也可以通过 or来进行折中解决"""
if type(value) == int:
return "int"
elif type(value) == float:
return "float"
else:
return "Unknow Type of {value}".format(value=value)

if __name__ == '__main__':
print(check_type(10))
print(check_type("10"))

print(check\_object((1, 3, 5)))  
print(check\_object({2, 5, 6}))

print(use\_type(10))  
print(use\_type((1, 3)))

判断继承链

class Person(object):
def __init__(self, skin, language):
self.skin = skin
self.language = language

class Student(Person):
def __init__(self,skin, language, name, sex, age, phone_number):
# 继承使用父类的析构字段
super(Student, self).__init__(skin=skin, language=language)
self.name = name
self.sex = sex
self.age = age
self.phone_number = phone_number

if __name__ == '__main__':
beimenchuixue = Student("yellow", "zh-hans", "xiaoMing", "male", 18, "15570911036")
# 判断实例xia_ming是否继承于 Persion
print(isinstance(beimenchuixue, Person))

print(beimenchuixue.skin)

判断实例对象由什么类型构成

class Class(object):
def __init__(self, student_names):
self.student_names = student_names

def \_\_getitem\_\_(self, item):  
    return self.student\_names\[item\]

python_class = Class(["QiNiuYun", "BeiMenChuiXue", "AliYun", "BaiDu"])

print(type(python_class))
print(type(int))
print(type(object))
print(type(type))